heh, just found out about http://www.ps3mediaserver.org/

installed it here (it is java based so it was a case of extract and run on my linux setup), and it worked with Media Streamer instantly. Sadly i have no extra DNLA/UPNP media renderer on hand, so i can't test if the N800 i am using could be used as a remote for that. But i expect as such, because there is a drop down menu above the player controls that i suspect would list any available render devices on the network.