MLB.tv, Dolby 5.1 for Netflix added to Apple TV 4.2 update
Just in time for the 2011 Major League Baseball season Apple adds MLB.tv to Apple TV in the 4.2 update. Also included in the update is Dolby Digital 5.1 surround sound for Netflix content. NBA League Pass seems to also be available but I don't see it in Canada so it may only be a US feature.
In addition to the sports and Netflix additions noted above, Apple also improved the on-screen keyboard, added additional slideshow themes for picture viewing and added the additional support needed for AirPlay integration with the iOS 4.3 updates.