Those who have used XBMC know that it is one of the greatest media centers ever created on any platform. No to long ago work started on porting this to linux and now more recently OSX.

The OSX version is progressing quite fast and is already very useable....

Who will be the first to get this up and running on their AppleTV?

Check it out here.....
http://www.osxbmc.com/
http://www.xboxmediacenter.com/forum/