CONFIRMED
There is a FAQ in the material being passed out to people at Blizzcon.
Heres a photo http://cache.gawker.com/assets/images/9/2007/08/996783595_9c1600687f-thumb.jpg
The guide mentions
- Introduction of the Death Knight as a playable dark necromatic character class.
- New zones, quests, items and monsters packed into the Northrend, an icy continent that is home to the Lich King.
- Raised level cap to 80
- New battelgrounds featuring siege engines and destructable buidlings.
- More character customization, including hair, dances and skin color.