I suspect yesterday morning will be one of those "remember where you were when..." moments. Our Monday morning alarm was set (having not disabled it for the bank holiday) so we woke to the headlines announcing the killing of US enemy number one in a daring raid into Pakistan.
I notice it hasn't taken long for the conspiracy nuts to come out of the woodwork. I've seen claims that Osama had been dead for some time and this was announced to boost Obama's flagging approval ratings. A lot also seems to being made of the fact that the body was buried at sea. They all suffer from the classic conspiracy fallacy of substituting something even more unlikely because the official story seems unlikely to them. It's purely an information problem - it's much harder to keep things secret forever than for a limited time.
Take for example the Whitehouse flickr photo-stream. The conspiracy theorists would argue "It's all staged! It means nothing". However the pictures identify 12-20 people in the most secure room in the world who would have to be in on the deception. That's 12-20 people who could potentially give the conspiracy away at any moment. And that doesn't include the rest of the people involved in an risky operation into a foreign country that left bits of a Black Hawk helicopter behind and witnessed in real time. Is it really plausible you would choose to violate Pakistani sovereign airspace risking and international incident to pretend you had killed Osama? Wouldn't it make more sense to stage the operation somewhere you had more control, for example in the Tora Bora mountains in Afghanistan.
There is of course the possibility that they thought they were going after Osama but didn't actually find him when they got there. However the official record has stated they used DNA evidence to be sure they got him, bringing more people into the slowly growing number that have to keep to the conspiracies version of the facts. Pretty soon you'll be in the same position as the Moon Landing Deniers that assume half of NASA where in on the lie.
Conspiracies do happen but they all tend involve a small number of people all equally tied the consequences of the conspiracy being revealed. Even then the group very rarely take the secrets to their graves. By all means question authority and keep an open mind to the possibilities, just don't leave your common sense behind when evaluating an even more far fetched explanation.