It may be that mp3 support was ripped out by upstream to avoid legal issues, but that may be resolved by a few packages available from dag such as gstreamer-ffmpeg.
Hmmm... I'm not sure what to make of this result. I installed the file from Dag that you suggested, and now Rhythmbox recognizes MP3 files, whereas before it wouldn't even load them.
But when I press play, it graphically shows the file playing (the timer counter moves along), but no sound comes out of my speakers.
I double checked and XMMS no longer plays MP3s either.
So, did the gstreamer-ffmpeg possibly do this, or might this have something to do with my recent fix to FireFox to get it playing sound?
Dave