The Apple TV is a very useful component of my home theater for the loft. The current firmware and iTunes allows for the ATV's use as Remote Speakers. This, combined with using the iPhone's REMOTE application, makes it effortless to play media in the house from wherever I am.
I have the ATV ganged to a Mac MINI that acts as the brain of the media hub. externals are ganged to MINI, with media (movies, music, etc)
I can use the ATV, as intended, from the couch to navigate the media directly (and my wife can order PPV movies from the iTunes Store when she wants to) which is good. But I also use the ATV as airTunes speakers when Im at my desk. I'm not using the display, so that stays off, but I pop into the ATV as speakers in my MBP's iTunes, and play music while I work. And then, the third scenario, I'm elsewhere in the house but on the wifi network, I can go into Remote on the iPhone, navigate the ATV directory, and play music that way.
Now, one caveat is that this can largely be accomplished with other technologies too. This is just my integration method.
Another is that I highly recommend you use the STREAMING method of media distribution rather than sync. You will otherwise run out of space in the ATV's meager HDD very quickly...