This is by far the biggest blow to al Qaeda that the U.S. has been able to inflict. I think the coming months/year of observed al Qaeda activity without one of their top men will tell us a lot about how the organization functions. Is it a vertical organization that requires specific instructions passed down a chain of command and which will be severely crippled by the blow, or is it a horizontal organization with autonomous cells, as many believe, that can continue to function for sometime without instructions from a central body? The answer will also, I believe, dictate what effect this has on the strength of the insurgency in Iraq, and the ability of the Iraqi government and the U.S. to bring order to the country.