I started to rebuild current rawhide for ppc (and a bit for ppc64).
I am now at the point where I have all packages required for
"yum groupinstall buildsys-build" rebuilt from rawhide.
The biggest problems so far was python (and python3), which could no
longer be built on Linux ppc:
https://bugzilla.redhat.com/show_bug.cgi?id=661510
http://bugs.python.org/issue10655
But that is fixed now. I will continue to rebuild more and more packages
for ppc and ppc64 and will soon post the results here.
Adrian