DVD deltaisos for Fedora 12-TC.1 -> 12-RC.1 for each of i386, ppc, and
x86_64 are now available at
http://thepiratebay.org/user/andre14965/
The sizes are 7.6%, 7.7%, and 5.5% of the full 12-RC.1 ISO size, resp.
The time to run applydeltaiso is approximately 3-4 minutes.
Applydeltaiso is in the deltarpm package for Fedora 11 and below, or in
the deltaiso package for Fedora 12.