More than anything he seems kinda inexperienced, which was the main criticism of him anyway.
But with the global economy in the shape it's in, the various wars going on, and the general mess Bush and his cronies have made over the last 8 years, I'm willing to suspend my doubts about him for a bit. Admittedly I'm a fan of his and was very glad when he was elected. But because of that, I (and a lot of people) have high expectations. If he truly fucks around and turns out to be nothing like he promised, people will turn on him very quickly. He promised change, so let's see it.