I've got a MacBook Pro and Apple TV, and I can search and select the movies found within the MacBook Pro's iTunes from the Apple TV's > Computers menu.
The problem is that when I try to play the movie from the Apple TV, it often freezes with the "loading" spinner, without playing the movie. If I hit the Menu button on the Apple TV remote, the Apple TV responds instantly, so it's not that the Apple TV has frozen.
If I instead start the movie from iTunes on the MacBook Pro, then display it on the Apple TV via AirPlay from the MacBook Pro's Display settings, the movie starts instantly and is shown on the Apple TV.
Why can I "push" the movie from the MacBook Pro to the Apple TV via AirPlay, but not "pull" the movie from the Apple TV's interface?