I am sure in time it will be supported, Hauppauge is pretty good about providing driver support for Linux.
I am looking into getting some PVR Cards to put in a few of my MD's to share the DirecTV Receivers onto LinuxMCE. I am guessing being as they aren't HD, etc, that probably the PVR-150's are what I need? Or is there a more recommended card? Would be sweet to get one that has the MPEG Decoder on it and output from the card, but not sure which models if any do that and if there is gonna be much benefit over just outputting from my NVIDIA. Any advice?