The Fremantle version of MediaBox Media Center is coming along nicely. The latest development version (2009.11.1) is now in extras-devel, so if you're brave enough to test out hot fresh unstable stuff directly from extras-devel, you're invited to give it a try (installing just MediaBox from extras-devel should be pretty safe).
The big news with the latest development version is UPnP MediaRenderer support. If you have a compatible (GUPnP-Media-Renderer has been tested to be compatible so far) UPnP MediaRenderer in your network, you can have MediaBox play on that renderer instead of your phone.
If the MediaRenderer supports it, you can even play local files from your phone on it, not only stuff hosted on another UPnP/DLNA server.
Eventually, this cool stuff will be available for N8x0 users, too, of course.