I rather liked this:

Well somebody is lying

Version 1:
According to various "witnesses" judged to be reliable by the Pakistani military (i.e. their own men) and totally believed by Pakistani politicians (Benizir Bhutto) Osama bin Laden died in the mountains of Tora Bora late 2001. No body was ever found presumably as it was buried beneath thousands of tons of rock. The report of this version was never confirmed or denied by Al-Qaeda primarily because it did not suit their purposes.

Version 2:
According to the current US Administration Osama bin Laden was killed during a raid mounted by US Special Forces on a compound in the Pakistani City of Abbottabad. Osama bin Laden was shot and his body was removed from the scene samples having been taken for DNA analysis, his body was then hastily buried at sea.

Common thing with both Versions is that neither can be independently verified or confirmed. The clever thing about Version 2 is that it forces somebody from the other side to react and that reaction came in the form a statement announcing that Osama bin Laden was dead (PS: It does not matter whether he died in 2001 or 2011)

Now we come to "purpose & timing" - May 2011

1. It obviously helps Barack Obama's re-election campaign in that no Democrat is going to be stupid enough to run against the "Man who shot Liberty Valance", but that only helps selection, to ensure making Barack Obama a two-term President this should have happened in 12 months time.

2. Helps get Barack Obama out of a pickle with regard to troop withdrawals from Afghanistan. When he reluctantly and criminally belatedly agreed to General Stanley McChrystal's request for more troops Obama, to appease Joe Biden, slipped in a rather poorly and inaccurately reported time line, that those "surge" troops would begin to be withdrawn in July 2011. In real terms that means that Barack Obama could bring back one single soldier and honour his promise, unfortunately that is not what the "MEEDJA" think having entirely misrepresented what the President had said - They expect thousands to be withdrawn. Well now that Al-Qaeda have announced that Osama bin Laden is dead President Barack Obama can immediately withdraw from Afghanistan the 17,000 to 23,000 troops currently serving in Afghanistan as part of US- Operation Enduring Freedom + 1 soldier "surged" into Afghanistan to serve the ISAF mission - And having done that Barack Obama becomes a "man-of-his-word" and a hero.

Reality:
- As far as Afghanistan goes Osama bin Laden and Al-Qaeda have been a total irrelevance since 2001;
- His death puts nobody any more at risk now than they were before or indeed at any time since 1970;
- It is in short a total non-event, about which nobody really gives a damn.