I have Muxic, my music player for Mac OS X, working to the point that it’s suitable for public consumption. There are still features to be added, but the basic previous/play/pause/stop/next stuff is working.
Caveats: it’s built against the macports xmms2 0.5 DrLecter, installed with the default prefix “/opt/local”, against the Mac OS X 10.5 SDK. Download and try the Muxic 1.0 Beta 1 binary, or check out the Muxic source with git:
git clone http://scarff.id.au/git/muxic.git