I believe in 'Ding dong, the witch is dead!' moments.
Congrats to all the obvious people: the special forces troops involved, the intelligence folks, to Obama, Clinton, Panetta, and so on.
Our thoughts and thanks should at this time also go out to all the nameless people who'll be pulling long hours right now rather than celebrating. OBL's death will have shaken many trees, signals will be flashing, networks will be lighting up. Lots of brave, smart people will have to be watching and listening, working towards the next great day rather than enjoying this one. Thank you.
Update May 4, 2011: There's been a lot of hand-wringing from certain quarters about OBL's death. Much of that relies on the idea that the only satisfactory end-game should have been a criminal trial of some kind. But, rightly or wrongly, the US and OBL alike conceived of their struggle as a war. The goal of war is to defeat/destroy the opposition/enemy. The enemy can surrender at any time, and POW and legal provisions then kick in immediately. But until that happens, the primary goal is to make the other guy die for his country or cause. That doesn't mean that 'anything goes' or that war crimes can't be committed etc.. But it does mean that identifying and killing your enemies - killing them so efficiently in fact that they start to surrender to you preemptively rather than keep up the fight - is the business you are in when you are fighting a war. Not ascertaining guilt but eliminating threats is the name of the game. Apparently, Obama seriously considered both drones-strikes and massive, B-52-delivered bombardment (20+ 2000-pound bombs) as alternatives to sending in special forces to get OBL. Those are the kinds of options that are characteristic of war, and only in the latter case is surrender-at-the-last-minute an option. Of course, 'long wars' conducted by irregular troops hiding among civilian populations pose many problems that make military action complicated and fraught in various respects. But, ha ha, it's probably much harder for irregulars living among civilians to last-minute-surrender than it is for regular military. OBL's style of war may in this way have come back to bite him.
And, yes, it's perfectly decent and reasonable to celebrate a victory in a struggle/war: someone who would eliminate you in a second if they could and who would not, did not ever surrender is gone. Ding dong. [It's probably better, however, to refrain from saying that successful military operations, even triumphs, do or reflect justice. You may hope that your win would be endorsed by some hypothetical, impartial adjudictor - God say - as an appropriate outcome, but you don't know that it would be. More importantly, you certainly aren't currently engaged in anything like impartial administration of sanctions etc..]
Update May 6, 2011: And, yes, there are many senses in which Bin Laden 'won' and got what he wanted. The most important thing for Bin Laden was to get US forces out of the Muslim Holy Land (Saudi Arabia), and he got that pretty smartly by late 2003. Go here for the basic Wiki treatment of the point, but, briefly: the US couldn't leave Saudi if Saddam was still in power in Iraq. Allowing the US to get out of Saudi, thereby stopping ticking off the likes of Bin Laden (and more generally putting some distance between itself and the problematic Saudi regime and getting more plausibly onside with both actual and possible modernizing/liberal democratizing forces in the Middle East) was therefore a major motivation for the US to invade Iraq. Insofar as Bin Laden had a more general goal of weakening the great Satan/far enemy, well, the multi-trillion dollar war on terror has been a huge hit hasn't it? and the damage done to the US's standing in the world (and history more generally) by its descent into legalized torture is enormous (trillions off Brand 'USA' I'd guess, if one tried to do a rough analysis of that sort). All of that's compatible with fast-growing economic inequality at home and financial crises being still more damaging (contracting HIV or hep C or becoming schizophrenic or getting Lou Gehrig's or... is still a horror even if cancer is your worst problem). But those are all sunk costs at this point, and can neither justify nor discredit taking actions against OBL in the present. And OBL's various 'wins' may evanesce. The US's standard of living and reputation will presumably eventually repair themselves. And, essentially the US calculated that 'giving OBL what he said he wanted over Saudi' (at least if Iraq didn't turn out to be a complete disaster) would over time unleash genuine modernizing forces in Saudi and elsewhere rather more than it would spur OBL's favored creeping Talibanization and theocracy. It's still too early to tell yet ('nothing ever ends'), whether the US calculation (prayer?) was correct (has been answered). Let's hope it was (has been).