I just finished setting up and configuring a mythtv media center.. I am impressed.. For an open source tivo this thing rocksI used the MythDora Distribution.. It took some work to get digital out of my soundcard and video out of my video card.. So far it works 100 times better than the windows media center box I had running.. the ability to use LVM to span the video partition acrossed multiple disks is nice.. It also has a mame front end... Theres now a port to get mythtv on the Mac Mini.. I have about 75 bucks wrapped up into it.. Nice little machine..
Im still having some difficulty getting some things working like the Mame front end.. the DVD ripping function is quite nice