Hope I'm not pre-empting Seth or anyone here, but I thought it worth
pointing out a very interesting blog post on planned future changes to
RPM:
http://stick.gk2.sk/blog/2009/10/rpm-summit-at-the-opensuse-conference-2009/
it lists several changes that were agreed in principle at a conference
between several Novell and Red Hat people. There's some stuff in there
which looks like it will likely lead to changes in Fedora packaging
policies once it's implemented, so if you want to get ahead of the
future it's a useful read =)