With all this hype over Spotify, it makes me think subsonic would be so much better if not similar with your own collection. I have a Mog account and recently started testing Spotify. I have to say I'm not impressed. I already stream "my" music with iSub. The n,y piece I would say would be me to have and I can't believe i couldn't find it in e Subsonic forums, is the the ability to post about a song or playlist on Facebook or Twitter or Google +. Also, stealing a page from Spotify - share a song or playlist via Facebook or Google+.
Just an idea - this could also be used with iOS or Android apps...
Erick