Looks like almost everything I have been looking for in a MP3 module. The only thing missing is the ability to open any file into the microcontroller. It does seem to have the SPI pins coming out to the connector, so I think you could do that with the SDfat library, but it would have been nice if the module did all the FAT stuff for you.
Of course the datasheets and info I have found are such horrible english that maybe it does support that somehow and it isn't clear.
I think I will order one as well. Would be nice to make a library for it, anyway.