I've been thinking about getting a new Apple TV in order to use the Plex app, but a friend showed me his Plexconnect setup, which basically hijacks the Trailers app on older ATVs and redirects it to access your Plex Media Server to stream your movies, music, etc.

Thus far I really like it and it seems to be working well. If you have an older Apple TV and don't like streaming from iTunes (which, frankly, has always been a little flaky), you might want to give Plex and Plexconnect a try.