All the new features of Apple TV — including movie rentals, a built-in music store, and big-screen access to Flickr photostreams and .Mac Web Galleries — are available now as a free software upgrade.

To Update: Apple TV automatically checks for new software every week. But if you’d like to upgrade your Apple TV manually, go to the Settings menu and select Update Software. Then just sit back, relax, and enjoy movie rentals and more from the comfort of your couch.

New in this version includes:
HD TV show:Purchase the leading HD TV shows directly from the iTunes Store. (US only)
Movie browsing by actor and director: Browse movies on the iTunes store by actor and director. Select “More” on the movie page and browse the actor and director list on the left to see other movies for that individual.
Chapter selection, alternate audio and subtitle: While playing a movie, press and hold Play/Pause to access chapter selection, alternate audio and subtitle display. The display shows the options available for the current movie.
Movie description: Press Up when playing a movie to display a description of that movie.
Genius playlist: To create a Genius playlist based on the currently playing song, press and hold Play/Pause to bring up the contextual menu and select Start Genius. Note: The Genius feature must first be enabled in iTunes 8.0.1 and synced with Apple TV.
On-The-Go playlists: To add the currently playing song to the On-The-Go playlist, press and hold Play/Pause to bring up the contextual menu and select Add To On-The-Go.
Music videos in playlists: Make playlists in iTunes combining your favorite music videos and songs. Play them back on Apple TV and let them play continuously.
Apple TV standby mode: From the main menu, press Play/Pause for about three seconds (or go to Settings > Standby)

Requirements:
OS X 10.3.9 or later, OS X 10.4.9 or later
iTunes 7.6 or later

Universal Binary