A lot of it is knee-jerk Don't-trust-the-government stuff, and a lot of it is transparent "Obama Sucks!!!" stuff. But in any rational person's mind, this issue should be closed.
Al Qaeda has confirmed it. Pakistan has confirmed it. Republicans in committees in both houses of Congress have confirmed it. Non-Partisans in every branch of our Armed Forces have confirmed it. These groups have nothing to gain from trying to make our Commander-in-Chief look good--in some cases, they're at a complete disadvantage by doing so. And if they're all working together in some huge conspiracy--well, that's the point where you start bringing Illuminati and Bank-Controlling Elders of Zion into your argument.
For example, if Osama Bin Laden had died 5 years ago, Al Qaeda would have taken this occasion to say "HA! You foolish corrupt Westerners--your government is lying to you! Bin Laden is lying peacefully in a grave in Mecca!" or something of that nature. They're still trying to spin the death to their advantage, but it's extremely telling they're not questioning the "American" version of the story. Of course, some people think Al Qaeda doesn't exist, which means that Bush blew up the towers, which means that Obama is in league with Bush, which means that Republicans and Democrats are on the same side, which means that Limbaugh and Maddow are teammates...and down the rabbit hole we go.
**Show us the pictures!** For conspiracy theorists, this is the biggest proof there is--if OBL had really died last week, they would release photos of his corpse. No photos, no Bin Laden. It's suspicious alright--TOO suspicious. If the White House had taken the time to commit an elaborate, international fraud on the world, do you really think they'd have forgotten to forge some really good pictures of a dead Osama? But, the crazies will say, that's exactly what Barack Obama WANTS us to think--he's being cunning by tricking us into thinking he's incompetent at large-scale subterfuge--right down to the shifting official story over the first few days! Except, conversely, we also take the changing story of the raid as face-value evidence of a conspiracy! Oh, and have you seen this rare slow-mo footage of WTC 7 "exploding"?! And...