p-mob, yes, your points are valid for Renderer and Server functionality, nice maybe but not must-haves. However, I think there's a stronger, valid case for Control Point functionality - MusicBee has great library control, search, filter and playlist features, it would be awesome to be able to use this to play audio on remote wireless streamers.
Steven, simple streaming would be great. Obviously full UPnP support would be the ideal to aim for (in my case to be able to see song titles on the client display and use the IR remote to pause, change volume). Can you direct me to the hydrogenaudio thread?