By coincidence, we happen to be in Berlin right now, and are determined to make our way to the Siegesaule monument and park to see him speak there tomorrow. 
I will try to blog about it tomorrow night after the event...the Germans are enthusiastic about Obama, but their grasp of American politics is reflected in a liberal weekly's opening of an article on Obama with a quote from a Morrissey song about his feelings about the United States. The layers of transnational pop culture are difficult to fathom.
As for Obama's essentially post-68 politics of liberal centrism, I'm not sure how that would go over in a city where the public schools recently abolished grades because that would damage the self-esteem of their students.
What the city does have is working class culture and working class clubs...the Berlin hipster scene is essentially apolitical...so go figure...