Didn't see this coming.
My first thought was, I'll be honest: too soon. But as Jonathan Adler, Robert Naiman, Steve Benen, and many others have noted, the Peace Prize is often as much about encouraging a "prospect" than it is about rewarding prior accomplishment. The goal of the Nobel is to create and foster momentum for changes they like to see (in the case of Obama, nuclear non-proliferation seems to be the heavy hitter), rather than waiting until the finish line has already been crossed. And the Nobel committee chair seems to have given the award in that spirit.
The second thought, though, was about the symbolic meaning of the award. I've cautioned against giving too much weight to symbolic victories, and I'll do so here as well. But, particularly in the foreign arena, I've talked about its importance as well, and I think it is noteworthy. The fact that President Obama seems to be an inspirational figure to many people worldwide is an asset of tremendous value to the United States worldwide. It is part of what is allowing America to slowly, painfully, reassert its moral authority to lead in the wake of the Bush administration. His election was a window into America's soul, and the world liked what it saw -- that we weren't going to keep electing Bushes year after year.
In a global community, it matters what your neighbors think of you. The Nobel Prize, if nothing else, is a symbol that our neighbors think well of us -- that they are proud to live in our neighborhood. That's a good thing, no matter how you slice it.
UPDATE: You'll note a pattern in the "world reactions" to Obama's victory. He gets congratulations from everybody except the President of the International Federation of Human Rights, Iran, Islamic Jihad, and the Taliban. Both the IFHR and Iran were actually somewhat neutral (the former wanted the prize to go to a Russian activist, the latter saying it is "not upset" -- but clearly not thrilled either). The last two, obviously, were apoplectic.
UPDATE #2: Meanwhile, in Israel and Palestine reaction is mostly positive. Prime Minister Netanyahu, President (and fellow Nobel laureate) Shimon Peres, and Defense Minister Ehud Barak all had warm things to say, as did chief Palestinian peace negotiator Saeb Erekat. In addition to the aforementioned Islamic Jihad, Hamas was displeased with Obama winning the award, and a chilly reception also went out from Knesset Speaker Reuven Rivlin (Likud), who called the decision "very strange".