from this command i get:
# CONFIG_VGA_SWITCHEROO is not set

zypper se vgaswitcheroo does not return any result for some reason

i'll stick with SP2 for dual display functionality and use SP3 repos only for updates such as firefox etc.; i'll loose the better performance of the SP3, which i think was visible on my system after the update.
SUSE should come with a fix for this lack of dual display proper support in what is a wonderful OS; that being said, i'm already back to SP2 and using dual display with the ATI discrete graphics.

thank you for your help, Malcolm&Co