Holy crap getting from 0 to 1 with gentoo took some effort, but now I have a fast booting and fast compiling (for a G4!) basic GNU/linux powerpc mac. Pretty cool.
Networking works, the kernel is rather new, nothing is broken, 'dmesg' doesn't throw any huge red flags. Kernel configuration was a pain, but so far so good. The hardest part was figuring out yaboot.