Obama: Citizen of the world. We're screwed '08

Sorry for all of the anti-Obama posts, but with the pub and coverage this guy is getting, its hard not to.
So Obama went to Berlin and addressed the Germans not as a candidate, but as a "wink wink" citizen of the world. A couple of things that spooked me here. First off, that was a political speech. From start to end. He got all of his political jabs in: global warming, one world government- it was in there he just didn't use those terms, America is bad, Iraq is wrong, America is mean, capitolism is bad, Bush is dividing and conquoring, basically all of the Democratic talking points. he was not campaigning though. The second thing is him being a "citizen of the world" Does he still qualify to be president if he is claiming another citizenship besides being a citizen of the USA? Do we even know if he is a citizen? I had to produce a birth cert to get my drivers liscense in North Dakota, he can't seem to produce an authentic one.