Eurogamer has a hands-on.

It’s all to do with orbs. These look a little like pearls, and move politely about the world of Fable 2 as if minding their own business. And they are minding their own business: every orb you encounter is somebody on your friends list who’s independently playing through the game. The orb shows their position, allows you to chat, gift them items, compare stats, and even boot them out of your world. It also allows you to invite them in to join you properly.

Fable 2 has a fancy pages on xbox.com, more coming later.

Gametrailers.com have some kind of Fable 2 gameplay montage.