I'm all for Americans winning international prizes, and especially the Nobel Peace Prize. I was also quite confident that Obama would win one as president, but I certainly didn't think he would win one so soon, with what Bloomberg calls "no concrete achievement to his credit." Similarly, Reuters describes Obama as "a president less than nine months into his first term, who has yet to score a major foreign policy success," adding that the award "came as a big surprise . . . "
One of the good things about the Nobel, especially in science and literature, but also the Peace Prize, is that they are about achievement, not promise. Even when the awards have been extremely problematic — recall Yasser Arafat — the recipients have done something, for good or for ill. This is especially true for American presidents, as John Miller pointed out in a good post earlier. Handing Obama the prize this early strikes me as a cheapening of the award. If I were Obama, I'd want to win such a prize in my fourth year (or preferably in a second term), rather than in my first.