I also want to know. They're coming to our local arena and I'm wondering what kind of crowd will be there. I work beer stands as a fundraiser for my charity. I'm guessing the crowd will mostly be too young to buy beer, but I'd be happy to be wrong....
My cousin (11) and I (19) just saw Fall Out Boy & All American Rejects (some other bands also) in concert on 3/19. It was a good concert. There was a lot of young girls there around my cousins age, not a heck of a lot around my age range. AAR were much better, in my opinion, then Fall Out Boy. However I have seen AAR a few times live before so I am biased.
I recently saw October Fall, their protege's who are on FOB's imprint label--same audience. The crowd was 13-20, mostly female.
I believe that October Fall joins that tour within the next week or so as the first opening act. They were OK, nobody I'd ever pay to go see, or go out of my way for--but I like hard rock, so I'm not a good barometer in that respect.