iTunes Extras and iTunes LP can now be viewed in fullscreen via Apple TV. iTunes Extras include such content as deleted scenes, interviews and interactive galleries. iTunes LP adds a more viewable content for full-length albums purchased from iTunes which may include live concert videos, artwork and other content.
Through the iTunes interface, Apple TV users can browse 8,000 movies (including 2,000 in 720p HD), and 50,000 TV shows. For audio, there is a catalog of 11 million songs and 10,000 music videos.
The software update also allows up to 12 generated Genius Mixes playable through your home theater system. For your photos, Apple TV now supports iPhoto Events and iPhoto Faces.
It should be noted the new features are only available if you are using iTunes 9 and Apple TV with the latest 3.0 software.
Although there is a link on the Apple TV webpage directing to the 3.0 update, it seems they haven’t updated the specs page yet.