As is typical, Blizzard rarely misses the mark on making big announcements and doing them right. This year they definitely hit the nail on the head. The announcement of Cataclysm (albeit upstaged by leaks a bit) was awesome. The reconfiguration of Azeroth is no face-lift, it is a complete re-creation of every zone in the game.
Cataclysm is really WoW 2.0 and changes everything. The old game will be gone, stats are being removed and changed. Whole character progressions will change, not to mention the addition of two new races and their starting areas. Almost every zone appears to be touched by the expansion (they've said some won't change drastically but will still be reworked). Are we ready for that?