Not sure if it makes more sense to post here or on the jinzora boards, but either way..
I finally got around to playing with Jinzora+Chumby. I've only done it via SSH, but it works perfectly with btplay. You can cut and paste a url and use btplay to play it:
btplay "http://192.168.0.134/music/mediabroadcast.php?jz_user=USR431ee16637cd6&sid=S4761ba13209e6&jz_path=T4720acffefcef&action=play&type=track&jza=141e6d2e03f40895888845a2f989e652&ext.mp3"
So it's time to do some real work..
There are 2 things that should be worth doing.. First, Jinzora has a jukebox component to let you play things on a slimserver, vlc, or mpd-based device. There could be a 'Chumby' jukebox to send music straight to the guy.
The second and more important one is to make Jinzora show up in the music channel. I have 0 flash skills, which is really too bad. It's probably best to do this in some way that allows other media-based webapps to work too. We have a REST-like API that can easily be extended to send things like playlist information and genre information. We can also add a call that gets a random MP3 or playlist given some parameters (genre, recently added, etc)
If anyone is interested in working on this, let me know. If not, I'll head back to the jinzora forums and work from there. If you want to play, I recommend checking out the Jz3 branch or better yet, an SVN snapshot.