Since upgrading to FC6, I can no longer select xscreensaver-provided screensavers from the KDE screensaver settings dialog. Checking the rpm spec file for kdeartwork shows that xscreensaver was removed from the build process. I still have all the xscreensaver packages installed, but now can't use those screensavers from KDE. Why this regression?
xscreensaver packages has been moved into Extras since FC6. You have to install kdeartwork-extras from Extras if you want xscreensaver support in KDE.