In case you missed it, The Plagueworks wing of Icecrown Citadel is now open. ZAM user IDrownFish has started a thread on the new wing in our WoW general forum, so feel free to add your experiences to the discussion.
The Crimson Hall wing is officially scheduled to open in two weeks on Jan. 19. If that timetable continues, it looks like we'll be facing the Lich King on Feb. 2. You can read more about the wings on Blizzard's Icecrown Citadel: The Frozen Throne page.