Today Apple updated its Remote iOS app with some additional options for playing content through the Apple TV.
You can now control iTunes Radio like music played through a shared iTunes library. The ability to browse purchased movies and TV shows from the iTunes Store has also been added. Apple added the option to stream purchased content last September, and now it’s easier to navigate an online iTunes library from an iOS device.
Update 4.2 to the Remote app includes bug fixes as well. It can be downloaded for free in the App Store.
Source: App Store