I think you would find running vmware on a unix (leopard) system, even if its hacked is just a bit more stable than running vmware in xp or vista.
The downside being the lousy virtual graphics driver which stops the use of media center.
If it all worked fine I would happily run vista in vmware so media center could keep recording my shows.
As media center is 100% better than any leopard alternative.
Sadly we are stuck with eyetv to record which is a pain to use with the remote.
Media center with remote and net epg is really a step up in tv watching. Its the closest to a tivo a computer can do.
although in myth tv on linux you can set it up to auto delete ads from your recordings.
As a note my media center plays all file types including divx mkv ogg and so on, all from the remote.
whereas eyetv will only play divx, and you cannot play the files direct from the remote you must use the mouse.
Things to think about if your interested in tv on the pc.
I just setup the autodownload free epg in eyetv but its still only half as good as media center.
I watch alot of manga which can be all different file formats, and watching show after show from my couch is alot better than having to use the mouse to start each new show.