We knew the exact location of Osama Bin Laden for about a year, and had surveillance set up around his hideout officially for over seven months.
Osama had a failing kidney and required regular dialysis and was on his death bed. Osama wasn't really a threat personally - it was the Al Qaida movement that was the threat. Obama's ratings had just began a free fall due to the unpopularity of the recent Obama-Care.
Obama had the icon of the still-active Al Qaida movement martyred on his deathbed, and then had the evidence/body dumped into the ocean - Chicago style. Obama's ratings recovered (back up to a near 50% overall approval rating). Osama's death showed the world slimy politics: Barack Obama's sacrifice to the voting Gods.