If merely reading the features list or glancing at the screenshots of World of Warcraft: Cataclysm doesn't do it for you, watching the announcement trailer surely will.

Cataclysm, the third retail expansion for WoW, raises the level cap and adds new races, areas, and dungeons. There's also a giant objective-based PvP zone in the vein of Wintergrasp from Lich King and an Archeology profession. You can get all the details here and pore over the first screenshots here.

Haven't seen any mention of when Cataclysm will arrive. BlizzCon's going on right now so perhaps they'll mention some sort of release window today or tomorrow. Here's the trailer.