/etc/X11/xinit/Xclients uses "which", but xorg-x11-xinit does not have a dependency on it nor does any of its dependencies pull it in. Fix: "Requires: which" or just hardwire GSESSION=/usr/bin/gnome-session and STARTKDE=/usr/bin/startkde in Xclients.
Changing version to '9' as part of upcoming Fedora 9 GA. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping
fixed in xorg-x11-xinit-1.0.9-5.fc11