A5X CPU... OK
iOS 5.1... OK
...but what about iOS 6? I really wish Apple would release iOS 6 and bring some OS X features in iOS now... such:
a File Manager (Finder), Multi-Users, Profiles/Groups, AirDrop, UI Themes, iPhoto/Aperture, Delete Photo in PhotoStream, True SMS/Mail Custom Sounds, Weather/Stock/Calendar as widget in Lock Screen, Voice Only Facetime Calls, Facetime over 3G, Turn the iDevice as USB Drive, RSS Reader in Newsstand, TV Streaming from iTunes "Live", Quick Access to Brightness/Bluetooth/etc.., Better Spotlight to list all files/apps/etc...
Spid
PS: If the Apple TV should have a CPU, it should be the A6 for the 1080p. So the A5X "could" be for the iPad2 or smaller 7.85" iPad for 720p.