Apple has updated the software for the US$99, streaming-only Apple TV to version 4.2 It adds support for AirPlay in iOS 4.3, support for Dolby Digital 5.1 surround sound when playing Netflix videos and the ability to access MLB.TV and NBA League Pass Broadband content
There are also new slideshow themes; you can view photos with the new Scrapbook, Photo Mobile, and Holiday Mobile slideshow themes. Apple TV 4.2 also improves the on-screen keyboard, letting you search and enter names and passwords more easily, according to Apple.
You can update the Apple TV software via iTunes.