Now that you offer up that reasoning, I would be interested in this as well. I don't use my Xbox too much for music, though, because I have FOUR MP101 music players (and I obviously get my playlists there). I mainly use my Xbox for streaming my DVDs from my server and that works fine.
Speaking of that, I think there may still be some issues with playing DVDs back, such as when streaming over library server (if on a high speed network, obviously). Last time I checked, it would give errors saying it couldn't find a file...it had a .dvd extension. So MC must be using an internal extension to specify the contents are an entire DVD and then it mistakenly actually looks for that file.
How can you get Xbox MC to connect to a UPnP server? Where is the option?
Also, my Xbox was setup 1-3 years ago. Do they release new software ever with more features and how hard is upgrading? Anyone know of a good source for XBMC's cheaply? I saw some on Ebay but they were around $100! The one I have now was purchased for $15 (with remote) from a friend...lol. Great Deal!