Fedora 12 Graphics [Update]
yum install mesa-dri-drivers-experimental
and a quick reboot later and my desktop seems to have actual 3D graphics support! It’s not perfect but it will certainly do until ATI gets in gear with their own Fedora 12 release.
Previously I was running KDE 4.3.3 on top of Fedora 11 (for the first experiment) and KDE 4.6.5 on top of Gentoo (for the second experiment).