(this article has moved here)
After the upgrade of my Fedora from Core 1 to Core 2, I noticed very serious problem – my keyboard layouts were missing, no switching – nothing! In KDE Control Panel -> Regional & Accessibility -> Keyboard Layout, the Available Layouts list was empty, also XKB options list was empty too.
I was astonished! After a long Google struggle, I found the solution here. It seems that the XFree86 to XOrg migration, which occurs in Core 2, has caused this problem. Seems also that Control Center expects to find the available layouts in the xfree86.lst file, while the new xorg layouts are placed in xorg.lst.
Execution of these commands as root fixed my problem:

cd /usr/X11R6/lib/X11/xkb/rules
ln -s xorg.lst xfree86.lst
ln -s xorg.xml xfree86.xml

Thanks to Ralf Ertzinger for his post – it saved my day!