I tried this out and it works nicely in conjunction with Canola's UPnP plug-in. I set Google Desktop to only index my media files. (I had uninstalled G Desktop a while ago because it made my computer a bit sluggish, but I figured I'd reinstall to try this out.)

Since I knew nothing about UPnP before, I was impressed that this all worked so easily. I'm not really sure that I will keep it installed, because I have most of the music I like to listen to on my N800 already, but its a neat thing to play around with.