From Fedora Project Wiki
PPC Specifics for Fedora
The PowerPC is now a "secondary architecture". This means that PowerPC distributions and updates are handled differently than the primary architectures. For a complete description of what the differences are between a primary architecture and a secondary architecture, refer to http://fedoraproject.org/wiki/Architectures.
Users with an interest in the PowerPC effort should consider joining the PowerPC/POWER/Cell Special Interest Group (http://fedoraproject.org/wiki/Architectures/PowerPC)