Leafing through the history of other terrorist movements, by far the most likely answer is “not much” for the death of one key individual rarely causes terrorist organisations or networks to collapse. Moreover, in Al-Qaeda’s case, it is a much more decentralised network than other groupings which survived the death of one or more key individuals.
More relevant are the continuing protests in Deraa and elsewhere in Syria. For the Syria government has been, alongside Iran, one of the major supporters of extremists and violence – in Iraq, in Lebanon and elsewhere.
Political change in Syria, if it happens, will be far more significant than the death of Bin Laden, even if it ends up taking as many years to come about.