unsolo is an amazing developer that is working on accelerated video for the PS3.
Currently, there's a working version of a video output for mplayer, and an Xv-driver is under development.

During a long and interesting conversation, we tracked down compilation issues with his spu-medialib on Ubuntu which ended up as a patch committed to subversion - so now it should compile on Ubuntu.

However, since I want to help out, I've created .debs for libps3fb and spu-medialib and also a mplayer-ps3 binary for your convenience. (See the summaries.)

When it comes to audio, Linux on PS3 falls short again as a media center, because of the 2 channel stereo support currently in the audio driver.
But I've been told that work is being done in this area as well.