Old thread I know but still...

Once you have added the google account to korganizer and have it all sync'd up you should be able to see your calendars. You then need to do as Nik Reiman said and right click on clock ->Digital clock settings ->Calendar ->Add check to "Show events".

I then found that to actually see the results come up I had to skip back a month and then forward, it then refreshed the events in the widget.