The BBC reports:
"Only very rarely has a person to the same extent as Obama captured the world's attention and given its people hope for a better future," the Norwegian committee said as the prize was announced.
"His diplomacy is founded in the concept that those who are to lead the world must do so on the basis of values and attitudes that are shared by the majority of the world's population."
Basically, for being such an improvement over the last president. "Oh thank God, that trigger-happy cowboy/smirking preppie asshole/fundamentalist apocalypsaholic can't invade anyone else!" "Hallelujah, now we won't be nuked into the Stone Age!"