I had to break out the install CD and start from scratch.
Well, that was fun. Fortunately, I didn't have any critical data on there at all.
Actually, you didn't need to do this, you never do with Linux. What you needed to do is force all those KDE related packages into reinstalling. yum is just a clone of apt-get, I suggest next time you type 'man yum'
the command in english would look like this...
"Yum, my dear pal, please FORCE the base package of KDE and all its dependencies to reinstall"
"Yes good sir."
from memory rpm -f /path/to/rpms/on/media/*.rpm will force a reinstall of everything if you do it from single user mode (init 1) after it you should be able to 'init 5' and have your shit back together without even rebooting.
You can also force remove packages so it doesn't take out their dependencies. For example, you might decide to build it from source to take part in a beta or whatever, same with Firefail (Firefox), if you want to get in on that community spirit thing.
With reinstalls however, and switching distros, because all the apps are virtually identical you should ALWAYS ALWAYS ALWAYS keep /home separate. That way, you can go "fuck it, I want debian" and install debian, tell its paritioner where home is and mark the "dont fucking format" button. This button being there goes all the way back to the damn early naugties and is always there except in Ubuntu's moron mode. Cheers not using that disaster!