Mixed MP3/Ogg Streaming
This is the problem, when a client, like XMMS, connects it negotiates the stream type. After this it just assumes all data after this point is of the same type. At no point can it switch content types. You can use something like a play list which lists multiple connections to simulate playing different formats in a row, the thing is this requires a reconnection to the server each time.
You can blame the two dominant protocols, SHOUT and ICY. One was created for the Shoutcast server and the other was created by the Icecast folks. Neither of them really considered the issue of carrying any other payload then MP3, or more to the point, changing content type in midstream.
At some point it would be great if Vorbis/Ogg became dominant because of the silly copyright restriction with MP3 that make the use of the lame encoder pretty questionable. It still has a way to go though since the code for bit peeling has yet to be finished and until that is completed, to down bitgrade an Ogg stream you have to decode it to some format like PCM and then reencode to Ogg (which is certainly not optimial for real time demands).
Last night while toying with ideas on how to proceed, while waiting to see if Question would make Ask Slashdot, I discovered something that does work after a fashion anyway. I setup shoutcast on the server(Linux). I am feeding shoutcast with Winamp's(NT) streaming component, from a playlist of all the MP3's and OGG's on the server. Winamp seems to be able to make the change back an forth between the two formats as it sends the data to Shoutcast(and presumably Icecast.) I can then pick up the stream on another winamp session(or freeamp or XMMS) on another machine. So it is possible in a way to do what I want if there existed a program that could do what winamp does, and have its playlist populated by a web interface while it is running.
Power Corrupts,Absolute Power Corrupts Absolutely, leaving one person(group)in charge is absolutely corrupt.