Another data point that conflicts with my theory
I've been reading recently about the special task forces who have been charged with hunting down bin Laden and others, and there was discussion of specia elitel guardsmen whose job it was to protect bin Laden. A training base for these guardsmen was raided last spring.
You'd have to agree that it would be odd for such a guard to be maintained if bin Laden were dead, unless they're being very extreme about maintaining the pretence.