Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
I recently did a post on cutting the cable which the article explained how you get XBMC 11.0 ontop of the ATV OS. Having run with this for a week or so it turns out that when streaming media from a NAS the playback becomes very choppy and out of sync audio and video occustrs a lot.
Thankfully there is another option however which involves removing the Apple TV OS and putting a Linux based OS onto the box which has been built specifically to work with an AppleTV containing the CrystalHD card.