Well, I got DebPPC on my Blackhawk recently. However, both the PReP kernel supplied with the latest unstable and the one I built from the 2.2.13 source deb have a couple problems:
Regular "Bogus Interrupt" messages that seem to be triggered by the keyboard. Bad BogoMIPS calculation? saytime and mp3blaster play sounds at a really high pitch. My 604/133 is reported as 266 BogoMIPS, which doesn't seem right. Also, have the clfbgen patches for Blackhawk been merged yet? Should I try to deb Xbh? Otherwise, I'm mighty impressed.