I'm using one with my Toshiba ET-1 projector. Not had much chance to play with it yet but it's looking hopefull.
I'm using DisplayConfigX to get matching res for the PJ (856x480) -
http://www.3dexpress.de/
VideoLan Client for playback -
www.videolan.org
I've set up a share on my main windows PC for DVD's, I then have a web page which I can browse on my mini showing all the DVD's. Select one and it links to a m3u playlist file that tells VLC to start DVD playback.
Processing power is limited so if you want to playback hidef material (720 or 1080) it has problems.
It's certainly proving harder to find information then for a PC (although as I'm new to macs I probably just don't know where to look), but it's so small and quiet I'm really happy with it.