Yes.

build and install the cross/powerpc-netbsd package, config the kernel
normally, and build with:

env PATH=/usr/pkg/cross/powerpc-netbsd/bin:$PATH MACHINE=macppc MACHINE_ARCH=powerpc make depend
env PATH=/usr/pkg/cross/powerpc-netbsd/bin:$PATH MACHINE=macppc MACHINE_ARCH=powerpc make all

You can try building userland, but I didn't have much luck. (Although
I might have been building against a bad -current.)

-- Dan

PS - Do we have a port-macppc web page maintainer who could be getting
all these FAQs down?