Xmms2 (client/server model) just made it into the Debian archives, so I guess it's getting close to ready. Seems to only include a command line interface at this point, but by the looks of their home page
they have big plans. I installed it and found it pretty easy to get tunes playing. Haven't messed with it much, but I assume that it'll be real useful to set up playlists using wildcards against my various music folders and that sort of thing.
Hopefully, I'll eventually be able to figure out how to use it like a shoutcast or icecast stream.