With the new Apple TV, and the fact that it’s streaming content from a library, there is one change that may affect some users. The previous model was like a living-room iPod, and acted as such: when you played music, then synced the device to your iTunes library, play counts and last played dates would be updated; this was the case even when you loaded a remote library on the old Apple TV. The new Apple TV, however, works more like sharing a library from another copy of iTunes on your network, and does not update these bits of metadata. In a way, this makes sense, but if you like to use playlists that depend on the play count or last played date, this could be a problem.
The solution is relatively simple, as long as you own an iOS device: using the Remote app on an iPhone, iPad or iPod touch, control your music playback from iTunes, and choose to have it stream to the Apple TV from the Speakers menu. Doing this, it will be iTunes sending music to the Apple TV, rather than the Apple TV sharing music from the iTunes library. It’s actually a bit easier to manage with the Remote app than having to turn on your TV set just to control music playback.
Note that for movies and TV shows, the Apple TV does update the played/unplayed status, so if you stream a TV show from your iTunes library, it’ll be marked as Played on your computer.
Learn more about iTunes 10 in my ebook Take Control of iTunes 10: The FAQ.