There should be some hidden configuration files there:
[gareth@gareth-desktop ~]$ ls -a /etc/skel/
. .. .bash_logout .bash_profile .bashrc .gnome2 .mozilla .zshrc
(Names starting with a "." are hidden in Linux.)
I'm not a KDE user, so I don't know which files to copy. There may be directories with names like ~/.kde* or ~/.config/kde*. However just blindly copying them will give new users more of your settings and personal info than you want. The best bet is to create a temporary new user, do nothing but set KDE as you want it for new users (don't enter any personal details etc.), logout and copy the KDE configuration folders to /etc/skel. Then remove the temporary new user.