Oh no, it has not even begun to hurt him. While the republicans are mad now, they actually got an amazing gift. From now on every one of Obama's international initiatives will be scrutinized and framed by the opposition and the media as an attempt to live up to his Nobel Peace Prize status instead of him acting as the President of the United States in the best interests of the United States. And regardless of whether this criticism is fair it will stick given american skepticism of all these european bureaucracies and european trophies. Especially in this case when americans realize full well that the award was not deserved and is therefore tantamount to a bribe. Your useful norwegian idiots shot themselves in the foot. Oh and btw, we can argue all day long but the world-wide gasp of disbelief when the award was announced should tell you all you need to know as to whether it was deserved. People are not stupid.
It's a perfectly understandable mistake: "With the exception of the Nobel Peace Prize, the Nobel Prizes and the Prize in Economics are presented in Stockholm, Sweden, at the annual Prize Award Ceremony on the 10th of December, the anniversary of Nobel's death. The recipients' lectures are presented in the days prior to the award ceremony. The Nobel Peace Prize and its recipients' lectures are presented at the annual Prize Award Ceremony in Oslo, Norway, also on the 10th of December." -- wiki