So what happens to al Qaeda now? First break down al Qaeda into its constituent elements: the hardcore leadership, the various affiliated groups that have some kind of organisational link to al Qaeda and the ideology, al Qaeda-ism.
The hardcore leadership has always been defined as bin Laden and his Egyptian associate, Ayman al-Zawahiri, and a few score associates in Pakistan. However, the ageing al-Zawahiri is apparently still alive has none of the charisma of bin Laden.
There are younger leadership figures. But people like Abu Yayha al'Libi, in his mid-40s, can never replace "the sheikh'.
The central leadership of al Qaeda has been rent by splits in recent years, often pitting Saudi, Egyptian and Libyan militants against each other. It is now likely to definitively fracture.
What of the affiliate groups or the "network of networks"?
Decentralising was always an integral part of the strategy of bin Laden. Al Qaeda was conceived as an umbrella group, channelling and focussing the diverse energies of the various groups active across the Islamic world in the 1990s.
This worked for a while but the main regional groups now - al Qaeda in the Arabian peninsular (largely the Yemen), in the Maghreb and in Iraq are largely independent of the main al Qaeda leadership.
Though the death of bin Laden will fundamentally change the landscape of contemporary militancy it will thus not necessarily have a major immediate effect on affiliate groups beyond discouraging their leadership by showing how, even if it takes 10 years, fugitives do eventually get caught and killed.
The final question is perhaps the most important. What will the effects be on the ideology?
Here the situation is less clear. Bin Laden's greatest success was to make his particular interpretation of radical Islamism globally known. There were other strands of militant thinking and strategy around in the late 1990s but 20 years of "propaganda by deed" made bin Laden's the dominant one.
A thriving "jihadi" subculture has emerged. Al Qaeda has become, in many ways, a social movement. Bin Laden's death means the removal of the iconic figure at the centre of this construct. This is undoubtedly important.
The most likely scenario in the future is continuing low level violence and threat shifting around the periphery of the Islamic world depending on local circumstances and the emergence of new leaders.
"My life or death does not matter. The awakening has started," Bin Laden boasted in late 2001. It will be at least another decade before we know if he was right.