I know enough to know I don't know enough, but that didn't stop me from trying the cheap and easy port that seemed to work with the 2.1 Gallery.
Grabbing Music.apk from the 2.1 ROM and installing from the SD card, which worked for the gallery, results in a parse error. : (
I guess some of the magic was done to the gallery - or they wanted us to use the gallery and be wowed by it to try to get us take an official OTA and give up root. NEVAR!