i recently did the same thing for a beige G3 i have. i actually installed the apple dvd/cd drive from a BW g3 and used pacafist to get the DVD player from the OS X install disks. the drive mounted DVDs on the desktop, but for some reason it will not play the dvds. I have not had the chance to figure out why yet. i have done nothing more then try to hit play, it failed, i went to bed.
LARS that is not true for my system. before i tried pacifist i just reinstalled the entire OS (X.2.8) after having the drive installed and blasting the disk and installing. it still did not install the player.