I think I heard of someone using mt-daapd to manage a music collection on a linux box through iTunes. You could then use rsync to synchronize it to your empeg.

For that matter, now that I think of it, you could use rsync with cygwin on a windows box to sync your iTunes folder. Check out cwRsync I'm not sure if you could get mp3tofid to work with cygwin, but it'd be worth a shot. Anyone who's used this stuff before care to comment?