I've never used Rygel....

Will PS3MediaServer work?

http://code.google.com/p/ps3mediaserver/

It is a java application. Java is now working on the N900. I run desktop java apps on my N900 such as Freemind, yEd, ganntProject. It would'nt surprise me if PS3MediaServer would run.

I think I got java se from here:
http://www.oracle.com/technetwork/ja...ads/index.html

I'm using ARMv7 Linux - Headful version. Also, there are other posts about getting full Java with more details than I am providing.