A first cut. Sorry if it's nothing earth-shattering. In descending order of importance:
1. For the world, the death of bin Laden provides important momentum for the United States and a brake on the prestige of al Qaeda. People around the world knew that bin Laden had defied the might of the American military and intelligence services, and this fact made the United States look impotent. That has been corrected, better late than never. Opposing the United States will seem like a slightly worse idea than it did before tonight.
2. For Americans, bin Laden's capture likewise boosts confidence in the military. The failure to capture or kill bin Laden was never received like the failed attempt to rescue hostages held in Iran, though the Bush administration's blunder at Tora Bora was far worse. But it represented an unfilled need, now filled.
3. The political ramifications: Minimal to nonexistent. The economy will tell the tale in 2012, and Obama—who had been getting relatively little foreign policy flak from the GOP —was not having a problem establishing his credibility as a foreign policy president on the right. Obama can add this to his list of accomplishments, but it's hard to see it moving voters.
(Addendum) 4. One more provocative thought: Does anybody really think that this happened because Obama is president? I'm open to details arguing the answer is yes, but I suspect the answer is no. I'm guessing this intelligence would have been gathered under any president, and any president would have made the same decision. So, yeah, you can point out that George W. Bush deemphasized capturing OBL as time went by, but I think that was ass-covering rather than a change in policy. So the biggest reason I think it won't have a political impact is that it shouldn't. I predict it will be a political non-event, and I think that's both fair and good. America could use a non-political celebratory event.