Apple just punched out Apple TV software update iOS 5.1 build 10A406e to bring it to the iOS 6 firmware generation for Apple TV 2G and Apple TV 3G.
Apple TV iOS 5.1 firmware brings new features such as support for Shared Photo Streams, ability to send audio content from Apple TV to AirPlay-enabled speakers and devices, and the ability to save multiple iTunes accounts and switch between them quickly.
Here is complete change log of Apple TV iOS 5.1 Firmware:
Shared Photo Streams – Accept invitations for Shared Photo Streams, browse photos and comments, and receive notifications of new content.
AirPlay – Send audio content from Apple TV to AirPlay-enabled speakers and devices (including AirPort Express and other Apple TVs). Also includes the ability to require an onscreen code to use AirPlay with your Apple TV.
iTunes account switching – Save multiple iTunes accounts and switch quickly between them.
Trailers – Search movie trailers. In the United States, see show times for local theaters.
Screen savers – New Cascade, Shrinking Tiles, and Sliding Panels screen savers.
Main menu – Reorder icons on the second page by holding down the select button on the remote.
Subtitles – SDH support for the deaf and hard-of-hearing as well as improvements to viewing and selecting subtitles.
Network configuration – Support for setting up advanced network options using configuration profiles. See http://support.apple.com/kb/HT5437 for more information.
Stability and performance – Includes general performance and stability improvements.
Download Apple TV iOS 5.1 Firmware For Apple 2G And Apple 3G