Sabaton was the headliner.
Regarding the fanbases not being able to stand each other.... I think people in Sweden are a little less sensitive to "sticking to their genre" than people are here. My buddy who went to the shows to see H.E.A.T is the biggest Dark Tranquiity fan ever born, and has no shame in supporting a "cheesy" 80's metal band. Maybe a little more respect for (good) music overall.
I like this attitude. I cut my teeth on "80's hair bands", but love a great deal of the current metal. With that said, there's nothing wrong with a person remembering his/her roots!
~Brian~