Sebt3 ported
XBMC as a PND, but it doesn't work very well, unfortunately - it's a bit slow, and it doesn't play videos. It may be that a new version of it would solve the video problem, and running it as a GUI would speed it up a bit.
Raspberry Pi has the advantage that it's video hardware can decode x264, whereas the Pandora would have to use its CPU (even if the DSP was got working, it only does baseline mp4). I'm fairly sure though, that XMBC uses ffmpeg for its playback engine, so it maybe that could be ported to utilise the omap framebuffer like the Pandora port of mplayer does.
That said, I'm not entirely convinced that XBMC is entirely suitable for the Pandora, because it's designed around the idea of a 10ft UI - i.e. you run on a big TV screen that you sit 10ft back from, not on a handheld's small screen.
If you just want to run content from a DLNA media server, you could try
PLUM