I think your app is really cool and I am getting allot of enjoyment from it so far, I just wanted to report that it works great via the UPnP service on a D-Link DNS-343 NAS which has a UPnP server built in.
It would be so cool if you could download songs to the iPod app via your app on the iPhone instead of connecting thought iTunes and a cable. Say, if you were listening to a song from your media server and wanted a permanent copy of it on your iPod for when you travel away from your WiFi. Then just press a button "send now playing to iPod library".
It sounds like a great idea but from what I have been hearing about Apple, they may never approve a link such as that beacuse it may be a conflict of interest with the iTunes app.
Just thought I would put it out there anyhow.
Look forward to your thoughts.