The Blasted Lands were Warcraft's most boring zone, saved only for the Dark Portal. Now it's got trees. A significant improvement.
The Abyssal Maw is a zone set almost entirely underwater. Early on, you'll be given underwater-breathing, and can walk along the surface of the ocean.
Blackrock Spire makes a return in Cataclysm. Remember repeatedly falling off the chain bridge? Yeah. Great times.
