A couple of friends of mine have Apple TVs and I had an opportunity to spend some time playing with one. The one I'm using has been "hacked" to enable Boxee, XBMC, etc.
First of all, it isn't really fair to compare an Apple TV to a full blown Media PC like mine (or Mac Mini). Even a minimal Media PC might be at least 2 times the price or more. Of course, a Media PC is also significantly more powerful and has features that (IMO) justify the price.
Nevertheless there is a lot of interest in Media Streamers (or Media Extenders) and the competition is intense. You can get some streaming media devices for as little as $100. The Apple TV is a compelling box at a little over $200 and is very hackable.
So, let's see what it can do and explore it's features.
More importantly, lets find out if you can cut the cord with an Apple TV!