OK, just so I'm sure I have this straight. The only way to watch a movie on iMovie Theater on the ATV is if it is uploaded to the cloud. And you can't upload any movie to the cloud that is longer than 15 minutes. WTF?? That's really crappy functionality. It would seem that one might be able to watch any movie in iMovie Theater on a Mac that is on the same network as the ATV, as opposed to having to reencode it for iTunes.