If you're a DK you can speed up this dungeon by extreme amounts by using Control Undead on the mob Ahn'kahar Spell Flinger Ahn'kahar Spell Flinger - NPC - World of Warcraft
You can use their ability Shadow Blast (Shadow Blast - Spell - World of Warcraft) As you are pulling the bosses. This ability will completely destroy the bosses, and if you have 2 dks with this Controlled Mob, you could 1 shot most of the bosses in the dungeon. It has a ~7.8 Second cast, but the damage is really worth it.
With 2 people using it on the last boss, you could kill it before the Insanity phase. Enjoy
You can use their ability Shadow Blast (Shadow Blast - Spell - World of Warcraft) As you are pulling the bosses. This ability will completely destroy the bosses, and if you have 2 dks with this Controlled Mob, you could 1 shot most of the bosses in the dungeon. It has a ~7.8 Second cast, but the damage is really worth it.
With 2 people using it on the last boss, you could kill it before the Insanity phase. Enjoy