Find it odd that the Americans would be able to conduct such an operation without the Pakistanis raising their eyebrows. It's far enough inside Pakistan that a few American choppers flying in, would be noticed by the military. But maybe I'm just underestimating the ability of the Americans and their tenacity... I do believe that someone high up in the Pakistani leadership/military knew that a operation was going ahead but perhaps weren't aware of the details - It's doubtful if the Americans even knew it was Bin Laden before they came face to face with him either. Then again, because of the trust issues and the accusations of Al Qaeda and Pakistani collusion it would have to be a very carefully handled intel exchange if there was one.
Like I said, I doubt we'll ever know the true ins and outs of the operation.