Check. This. Out: http://www.worldofwarcraft.com/cataclysm
It's beyond all imagining. I thought I'd want to take screenshots/video of the old zones for nostalgic purposes, but now I know I have to. Azeroth as it's currently known will be no more once this hits. Old zones will be completely redone, and I don't mean new skins and an extra hill or two... I mean straight up, full on armageddon. Shattered lands, lava and molten rock everywhere, and giant scars in the land.
Thankfully, we'll get to use our flying mounts in the old (now new) world.
But, God, this is so awesome. I haven't played in about a week, but I'll be jumping online tonight for sure. Leveling up Seona seems to be a must. And I'll hit up Yrovi, too. I'll be rerolling a few toons (Undead Hunter FTW!!), and definitely picking up one of the new races to level to cap. At least. On top of everything else, it appears that there will be other new things, like guild leveling and a new profession. The guild leveling thing interests me... I wonder what it's all about and how it works. Oh! And there's something called the "Path of the Titan" for players. It sounds like a crazy-epic questline or something.
I'm so freaking stoked. :D
Edit: So, Goblins and Worgen will start at level 1, but their opening areas are going to "top the Death Knight starting area" with full on cinematics (like Wrathgate) and the like. This expansion might as well be called World of Warcraft II.