I have upgraded from openSuse 12.1 to 12.2
It was OK except a few things which were easily solved but one :
When trying to change user on KDE, that is doing ( session)Quit > Disconnect
from the Application Launcher, the system closes the KDE session, goes out
of KDE and re-opens in console mode.
I am not sure about this, but at the KDM login screen, find Session Type and select KDE Plasma Workspace. The setting should be remembered for the net login.
Also in /etc/sysconfig Editor (you can edit this from YaST), set Desktop > DEFAULT_WM to kde-plasma