Thanks for the info Andrew! I will disagree with you on one statement though:
This is *very* possible in LinuxMCE, with a built in UPnP server. I understand that your implementation will only work with your Dianemo systems though.
I wasn't saying it wasn't possible in LinuxMCE - of course you could implement something similar. What I meant was it would not be possible to integrate our UPnP code without also integrating all of our other underlying changes to the media system - which would definitely break a lot of existing code.
All the best