oh great ! I'll be waiting for it!
I just replied to your first email and I sent you the code that I wrote so far, but you may not need to look at it if you develop your idea. At the moment I can get a 128k/s icecast stream without a problem using a baudrate of 230400, but only if I redirect it to the USB port. Copying to the rMP3 SD card fails. If you can manage to make a direct protocol, then I think it will be very straightforward for me to finish.
The main issue with a ethernet streaming mp3 player is the buffering of data packets. The AVR has only 2k of RAM which is not enough to buffer the TCP/IP packets form the ethernet controlller, buffering is needed as packets form the internet can be corrupted etc, so the ideal setup would be the avr connected to the ethernet controller and additional ram available via a SPI interface. The SPI interface can also be shared with the vs1053 mp3 decoder chip to complete the ethernet based mp3 streaming media player. This kind of setup is seen on the vs1053 page for the PIC family and ARM.http://www.watterott.net/projects/webradio-armhttp://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en536047
The key issue is the code to interface the external SRAM to buffer the ethernet packets. If that can be sorted out, you will have your avr based streaming mp3 player