Incase anyone missed this - It's on the blizzard website.
World of Warcraft Community Site
GOGOGO read.
Here are some of the more 'cool bits'
Icecrown Citadel will feature a massive five-player dungeon sprawling across three wings of the citadel's foundation. While the Lich King's attention is focused on the Argent Crusade and the Knights of the Ebon Blade ripping through the front gates, players will be tested as they assist Jaina Proudmoore (Alliance) and Sylvanas Windrunner (Horde) in infiltrating the citadel through an alternate entrance.
Bosses
* Falric and Marwyn: Captains for Arthas Menethil in life, Scourge commanders for the Lich King in death, Falric and Marwyn will be summoned to the Halls of Reflection for one purpose: destroying all intruders.
* The Lich King: Sylvanas, thirsty for vengeance against the corrupted prince who sentenced her to an existence as an undead monstrosity, and Jaina, eager to find a flicker of Arthas's soul locked somewhere within the Lich King, have brought their hand-picked allies to this final confrontation. Arthas's true power may only now be discovered. Is there any hope in this mission, or does only death await?
Normal and Heroic versions of the dungeon will be accessible to players, although each wing will be considered a separate instance; therefore, on Heroic difficulty, each wing will have its own separate lockout timer. All-new rewards -- including item level 219 (normal) and level 232 (Heroic) loot