very nice work!... if we can (eventually) get an rr clone written in c with builtin music and video player and support all the features and skins that rr supports and would run a lot faster, that would be perfect!
I tried it out and the only thing I noticed bad about it so far was the general slowness (I'm guessing it would be fixed once you optimize the skin loading) and that it takes up 50+ mb of ram...
EDIT: oh, forgot to say, but I noticed you mentioned XBMC on xbox... it's good that you're taking ideas from that excellent piece of software!
EDIT2: one more thing, since I already mentioned XBMC, why not use winamp's in_mp3.dll like XBMC does for music playback (and leave mplayer for video)?