As has been covered at length in this corner of the internet, I voted for Mr. Obama last year almost exclusively because I saw in him a hope to improve the trajectory of US foreign policy, and by extension, to promote the cause of peace in the world. (I know--I feel terribly corny having just written such a sentence.)
But it should be said that there was--to put it mildly--vast room for improvement on the front of "improving international cooperation". The bar was pretty damn low.
I know the Nobel Peace Prize has often been absurdly political for its entire history; this is nothing new. So I'll just leave it at this: I sincerely hope Mr. Obama actually accomplishes something in the next 3-7 years to deserve the prize he was awarded today.
OK, one more thought on this. How often is it that a course of action is both politically savvy and the Right Thing to do? Declining the prize would be exactly that.