yeah this looks great. If it turns out to be a fit for the company I'm working for I could ask them to turn their Flash server budget into some R&D on this and I'd gladly submit anything of value to the codebase.
I wrote up a few ideas back when KPCC was applying for a Knight Foundation News Challenge grant:
http://ewr.is/2012/03/1788-taking-radio-beyond-the-play-butt...
StreamMachine supports all the cool bits underneath, but we've never gotten a chance to do the client integration to really take it to the next level.