Apple TV is the shit!!!!!
A jail broken apple TV running XBMC media center is utterly amazing!!!!!!!!!!!
I've got a Mac mini connected to my primary tv/entertainment center and am using that as a server for my entire media library, movies, music, pics, etc...
Using XBMC is the key, it brings everything together In one place with an amazing UI!
The cool thing is, no need for a wireless keyboard or mouse, I use an app called mobile mouse that turns my iPad 2nd and 3rd gen into a track pad and keyboard. The best part is that I don't have to use the TV to access my desktop to do anything. If the tv is being used I can use the splashtop app pull up my Mac desktop up on my iPad to access and do what ever I need to.
I have an apple tv connected to a tv in another room that my son uses. It has XBMC on it as well and can access any of the media on any of the hard drives.
I also use PLEX to stream to multiple devices using wifi or 3G or 4G. My brother in green bay can access my media files through his iPad and Mac as well.
FYI, I do all this without using iTunes at all, I really don't use iTunes for anything.