I'm going to repeat what I said earlier for emphasis.

NONE OF THIS IS MY WRITING. Every speck of this came from the lovely folks at WoWHead, via ArgentSun explanations, or comments from generous readers - all from WoWHead. The ONLY thing I have done is compile it in one spot, for those of us who are lazy and need one place, and also for those of you who cannot access wowhead from work and are desperate for new patch stuff today.

Lord Marrowgar

Icecrown Citadel

The Lower Spire
Lord Marrowgar
Lady Deathwhisper
Gunship Battle
Deathbringer Saurfang

Overview

Being the first boss of a new raid, Marrowgar is not an overly complicated fight. You will need at least one soaking offtank, because of the Saber Lash cleaves (think Nalorakk). He will also shoot a line of Coldflame at a random target. The projectile moves like a spear until it hits a wall, but inflicts large amount of damage per second to anyone caught in it - simply making a few steps aside is enough to avoid it. The tanks are immune to Coldflame. Bone Spike Graveyard is another thing to watch out for - Marrowgar will choose 2 (25-player: 3) people and impale them on ice spikes. The people will take some physical damage, become incapacitated, and continue losing 10% health for every second they remain impaled. The DPS should kill the spikes as soon as possible.

The last thing to watch out for is the Bone Storm. A few seconds before it's cast, Marrowgar will emote a raid-wide warning "Lord Marrowgar falls apart and his bones begin to spin!". The spell works very much like Stormcaller Brundir's Lightning Tendrils - Marrowgar chooses a random target and pursues them for a number of seconds, moving in a whirlwind of bones, switching his targets periodically. Anyone caught by the whirlwind will take physical damage and have a physical damage DoT applied to them every 2 seconds. Must be avoided.

Normal 10-Man Abilities

• Saber Lash - Inflicts 200% weapon damage split evenly between the target and its 2 nearest allies.
• Coldflame - Inflicts 6,000 Frost damage every 1 second for 3 seconds to anyone caught by the moving line of frost.
• Bone Spike Graveyard - Hurls a spike at a random player, impaling all players between the boss and the target on Bone Spikes, inflicting 9,000 direct Physical damage, and additional 10% health as damage every 1 second until the spike is destroyed.
• Bone Storm - Inflicts 6,000 Physical damage every 2 seconds to players caught in the Bone Storm. The entire storm lasts ~20 seconds.

Lady Deathwhisper

Icecrown Citadel

The Lower Spire
Lord Marrowgar
Lady Deathwhisper
Gunship Battle
Deathbringer Saurfang

Overview

The key element of the fight is management of DPS, that will need to be split between the adds in phase 1, and Deathwhisper's mana shield.

During phase 1 Lady Deathwhisper will have a mana shield that will absorb all the damage done to her. She will attack the raid with Death and Decay, Shadow Bolts, and occasional Mind Controls, none of which should be too dangerous. The second component of the phase, the adds that come, could cause troubles.

Adds will come in waves from the sides of the room - 3 Adherents and 3 Fanatics total per wave. Adherents can only be DPSed through physical damage, and Fanatics - only by spells. The important things to watch out for with the Adherents is the Shroud of the Occult + Deathchill Blast combination used right after Lady Deathwhisper casts Dark Empowerment on them. Curse of Torpor should be removed as quickly as possible, and Dark Martyrdom should be avoided. For the Fanatics, a paladin tank is recommended. They are nothing special overall. Burn them when they have Vampiric Might, and run away from Dark Martyrdom.

Phase 2 begins when Lady Deathwhisper's mana barrier has been drained - which means that either some of your DPS should stay on the boss, or you should have everybody clear the adds quickly and use the time until the next wave to burn the boss' mana. Either way, in phase 2 she becomes active and a tank needs to pick her up quickly, as there is no threat reset. A second tank will need to be ready to pick up the boss, since she will periodically debuff her current tank with threat generation reduction debuff. The two will switch every 2-3 stacks. Everybody else should be mindful of the Vengeful Shades that will be spawned and will chase people - get away from them, let ranged DPS kill them from afar. Melee DPS might want to set up an interrupt rotation, since the Frostbolt can hurt a lot - or you can have a tank with 1-2 pieces of Frost resistance gear, Deathwhisper is not a very tank-heavy fight.

Normal 10-Man Abilities

Lady Deathwhisper

Phase 1

• Mana Barrier - Absorbs all damage done to Lady Deathwhisper, draining her mana instead.
• Shadow Bolt - Inflicts 7,438 to 9,562 Shadow damage to the current target.
• Death and Decay - Inflicts 4,500 Shadow damage every 1 second to enemies within the area of the spell. The entire spell lasts 10 seconds.
• Dominate Mind - Mind Controls 2 players, increasing their damage by 200% and healing by 500%. Lasts 12 seconds.
• Dark Empowerment - Empowers a random Adherent or Fanatic, causing them to deal area damage with spells. Also makes the target immune to interrupts.
• Summon Reanimated Adherent - Transforms a dead Cult Adherent into a Reanimated Adherent.
• Summon Reanimated Fanatic - Transforms a dead Cult Fanatic into a Reanimated Fanatic.

Phase 2

• Frostbolt - Inflicts 40,950 to 43,050 Frost damage to the current target. Can be interrupted.
• Death and Decay - Inflicts 4,500 Shadow damage every 1 second to enemies within the area of the spell. The entire spell lasts 10 seconds.
• Dominate Mind - Mind Controls 2 players, increasing their damage by 200% and healing by 500%. Lasts 12 seconds.
• Touch of Insignificance - Reduces the target's threat generation by 20% per application. Stacks up to 5 times.
• Summon Vengeful Shade - Summons a Vengeful Shade from the body of a dead Adherent or Fanatic.
• Vengeful Shade - Pursues a random target and casts Vengeful Blast when in melee range of that target.

Cult Adherents & Reanimated Adherents

• Adherent's Determination - Makes the Adherent nearly immune to magic damage. Passive.
• Frost Fever - Inflicts 2,375 to 2,625 Frost damage every 3 seconds for 15 seconds, and reduces attack speed by 14%. Disease.
• Shroud of the Occult - Deflects all harmful spells back to their caster. Also prevents cast interrupting. Absorbs 50,000 damage before breaking. Cast when Empowered.
• Deathchill Bolt - Inflicts 6,938 to 8,062 Shadowfrost damage.
• Deathchill Blast - Inflicts 9,250 to 10,750 Shadowfrost damage to all enemies within 10 yards. Cast when Shrouded.
• Curse of Torpor - Increases a player's spell cooldowns by 15 seconds. Curse.
• Dark Martyrdom - Inflicts 12,000 Shadowstorm damage to players within 15 yards. Cast near death.

Cult Fanatics & Reanimated Fanatics

• Fanatic's Determination - Makes the Fanatic nearly immune to physical damage. Passive.
• Necrotic Strike - Inflicts 70% weapon damage and applies a debuff Necrotic Strike that absorbs the next 9,000 healing done to the target.
• Vampiric Might - Increases all damage by 25% and heals the Fanatic for 300% of the damage he inflicts. Cast when Empowered.
• Shadow Cleave - Inflicts 14,250 to 15,750 Shadow damage to enemies in front of the Fanatic.
• Dark Martyrdom - Inflicts 12,000 Shadowstorm damage to players within 15 yards. Cast near death.

Gunship Armory

Icecrown Citadel

The Lower Spire
Lord Marrowgar
Lady Deathwhisper
Icecrown Gunship Battle
Deathbringer Saurfang

The Icecrown Gunship Battle is a unique event that serves as the third boss encounter in the Icecrown Citadel. During the event the Skybreaker and Orgrim's Hammer race to the second level of the Citadel. All players can talk to a goblin/gnome on their gunship and obtain a jetpack that allows them the jump between the two ships.

Overview

Winning the battle between the two gunships will require your raid to be carefully split between people defending your own ship, and people assaulting the enemy one.

Players staying on your faction's ship have two things to take care of. First, 3 people will need to man the cannons and attack the enemy ship. Rcoketeers will mark areas on the board and shoot (slow) rockets at them - it's easy to move away, do so. Axe Throwers/Riflemen will also shoot at people from across. Every 25% of the enemy gunship a mage will appear and freeze all of your cannons. The assaulting players will need to deal with him (see below), while the defenders deal with the squad of Reavers/Marines and a Sergeant that is being teleported. Both types gain damage and attack speed over time - so the longer they live, the more dangerous they will become. It is probably a good idea to have your ranged DPS defending, as they can avoid the Sergeant's whirlwind, and can also help the attackers (without using the jetpacks) when given an opportunity. As soon as the mage is dead and your board is secure, 3 of the defenders can re-enter the now-working cannons and continue shooting at the enemy's gunship, restarting the cycle.

The attackers have a couple of things to worry about as well. Saurfang/Muradin will try to annihilate your raid - have a tank on him, and be mindful of the stacking Battle Fury buff, which increases the commander's damage. If the buff starts getting to high, you will need to leave the ship for about 20 seconds and let it fall off. DPSing the leader is useless - have your DPS quickly burn the mages whenever they appear, and killing Axe Throwers/Riflemen and Rocketeers/Mortar Soldiers when no mages are present.

Normal 10-Man Abilities

Gunship Cannon

• Heat - Gunship Cannons use Heat as a resource. Cannon Blast generates heat, Incinerating Blast consumes it. When a cannon's heat level reaches 100, the cannon becomes inactive for some time.
• Cannon Blast - Inflicts 1,000 Siege damage and generates 6-10 Heat.
• Incinerating Blast - Inflicts 1,000 Fire damage and additional Fire damage per point of Heat. Consumes all of the cannon's heat.

High Overlord Saurfang & Muradin Bronzebeard

• Battle Fury - Increases all damage by 10%, stacking. Lasts 20 seconds, refreshed with each stack. Applied every time Saurfang or Muradin strike a target.
• Cleave - Inflicts 110% weapon damage to up to 3 targets in front of Saurfang of Muradin.

All Troops

• Experienced - Increases damage by 30%, and attack and casting speed by 20%. Applied if a soldier has been alive for more than ~20 seconds.
• Veteran - Increases damage by 60%, and attack and casting speed by 40%. Applied if a soldier has been alive for more than ~40 seconds.
• Elite - Increases damage by 120%, and attack and casting speed by 80%. Applied if a soldier has been alive for more than 60 seconds.
• Desperate Resolve - Increases armor and attack speed by 60%. Applied when a soldier's health gets below 20%.

Kor'kron Sergeant & Skybreaker Sergeant

• Bladestorm - Inflicts weapon damage to up to 4 nearby targets every 1 second for 6 seconds.
• Wounding Strike - Inflicts 200% weapon damage and reduces all healing done to the target by 25% for 10 seconds.

Kor'kron Reaver & Skybreaker Marine

• No unique abilities.

Kor'kron Axethrower & Skybreaker Rifleman

• Hurl Axe - Inflicts 3,800 to 4,200 Physical damage.
• Shoot - Inflicts 3,800 to 4,200 Physical damage.

Kor'kron Rocketeer & Skybreaker Mortar Soldier

• Rocket Artillery - Targets an area on the players' ship and launches a rocket there. The rocket travels for a few seconds, causing an Explosion when it lands, inflicting 6,300 to 7,700 Fire damage to players and Siege damage to the gunship.

Kor'kron Battle-mage & Skybreaker Sorcerer

• Below Zero - Freezes the enemy gunship's cannons, rendering them inactive. Channeled spell. Cannot be interrupted.

Deathbringer Saurfang

Icecrown Citadel

The Lower Spire
Lord Marrowgar
Lady Deathwhisper
Gunship Battle
Deathbringer Saurfang

Deathbringer Saurfang, formerly known as Dranosh Saurfang, son of the most prominent orcish general, is the final boss in the entrance to the Icecrown Citadel. He is also the last boss players can fight in the first week(s) of the new patch. After him the raid instance splits into 3 wings (Crimson Halls, Frostwing Halls, Plagueworks), and progression between the wings becomes non-linear.

Overview

Saurfang is a tough fight. He does a lot of damage, he heals a lot.

There is only one phase to the fight, but that phase will really strain your DPS and Healers. Two tanks are required for this fight. The OT will be helping to kite the Blood Beasts and taunting Saurfang off the MT when they get Rune of Blood.

All players need to be spread out, so Blood Nova doesn't hit multiple people. Several hits mean Saurfang will gain more damage and energy through Blood Power. Boiling Blood is just a DoT healers will need to take care of - the fact that it does physical damage suggests that it might be removable by Hand of Protection and Iceblock. Use those abilities if you can, they will keep the Blood Power stack lower.

When Rune of Blood happens on the MT, the OT should taunt the boss at least for the duration of the Rune - or the MT can pick the boss back up when the OT gets Rune.

Mark of the Fallen Champion will happen several times during the fight. Players marked with it will likely need massive heals and survival cooldowns. Hand of Protection and Iceblock help here too, you might want to save them for Marks instead of Boiling Blood. The damage is transferred after armor reduction, so a tank with high physical damage reduction is especially helpful. With all the healing going on in this fight, it is very important not to lose people - especially when they heal the boss even more. The mark is permanent, so it is possible that you will have somebody die.

And finally, the Blood Beasts. Saurfang will summon them around him, and he will summon them frequently. You can either assign certain DPS to peel off the boss and kill the adds whenever they spawn, or you can have everyone moving off the boss. The balance between boss and adds seems similar to the last phase of Yogg-Saron's encounter. I would recommend having just enough DPS to kill a set of adds before the next one spawns, and everybody else staying on the boss at all times.

Normal 10-Man Abilities

• Blood Link - Triggers Blood Power every time Saurfang or his Blood Beasts inflict damage with an ability. Also increases Saurfang's energy by 1.
• Blood Power - Increases damage and size by 1%. Applied through Blood Link.
• Mark of the Fallen Champion - Causes Saurfang's melee attacks to hit the marked target as well as the tank. The marked player takes 4,275 to 4,725 additional Physical damage from each attack. If a marked player dies while the Mark is up, Saurfang heals for 5% of his maximum health. Cast when Saurfang reaches 100 energy through his Blood Link energizing.
• Frenzy - Increases Saurfang's attack speed by 30% and size by 20%.
• Boiling Blood - Inflicts 5,000 Physical damage every 3 seconds for 24 seconds. Used on a random target.
• Blood Nova - Inflicts 7,600 to 8,400 Physical damage to a random target and all players within 12 yards.
• Rune of Blood - Marks a target with Rune of Blood, causing Saurfang's melee attacks against that target to leech 5,100 to 6,900 health from them, and heal the Deathbringer for 5 times that amount. Lasts 30 seconds.
• Call Blood Beast - Summons 2 Blood Beasts.
• Scent of Blood - Saurfang buffs the Blood Beasts, causing them to reduce the movement speed of all nearby players by 80%, while increasing the Beasts' damage by 300%. Lasts 10 seconds.
• Resistant Skin - Decreases damage taken from AoE effects by 95%, from diseases by 70%, and from Shadow spells by 100%.