With Osama bin Laden dead, al-Qaeda no longer has the face that came to symbolize the group behind 9/11.

But bin Laden's sudden demise at the hands of U.S. black operatives sets off a round of questions of its own: Who will fill the void he leaves in al-Qaeda? Or does his killing leave a void at all?

And what will happen with a group many consider has evolved from a more defined hierarchial organization into a vast array of groups — or franchises — with their own agendas, spread around the world?

"In many ways, I don't think it's going to change a lot in the sense that bin Laden has been probably a little bit removed from the main operations of the group, anyway," says Dane Rowlands, a professor and associate director at the Norman Paterson School of International Affairs at Carleton University in Ottawa.

"They in a sense already delegated a lot of the authority to groups which basically just claim the al-Qaeda mantle in their region and began operating on that basis."

And, says Rowlands, there's the suggestion that al-Qaeda's second-in-command, Ayman al-Zawahiri, was already in effect the operational leader.

Al-Zawahiri is a controversial figure in his own right. While the man who was tried in connection with the assassination of Egyptian President Anwar Sadat more than 30 years ago was considered bin Laden's No. 2, observers differ on the impact he may have on al-Qaeda's future.

Al-Zawahiri: 'Dyed-in-the-wool terrorist'

"Zawahiri is clearly poised to step into bin Laden's shoes," Bruce Hoffman, a terrorism expert at George Washington University in Washington., D.C., told National Public Radio. "He has the street cred of being a dyed-in-the-wool terrorist ever since he was a teenager."

But former CIA analyst Marc Sageman, who wrote Understanding Terror Networks and Leaderless Jihad, says al-Zawahiri is a "very divisive and polarizing character, and al-Qaeda terrorists may refuse to follow his lead."

"They have sworn bayat (allegiance) personally to bin Laden and not to Zawahiri," Sageman said in a release Tuesday.

Rowlands had been studying what happens to terrorist and insurgent groups when their leadership is targeted long before bin Laden was shot and killed in his heavily fortified compound in Pakistan.

"The interesting thing that we've found is that in general, you can't predict. There's a huge range of effects," says Rowlands, who has been working with a data base that includes 250 groups.

If a group depends a lot on the operational leader, his removal could lead to a permanent or temporary decline in activities. If the group is a bit more robust and bureaucratic in its structure, "you can have the opposite effect," says Rowlands.

Different organization

So where would al-Qaeda fall on that spectrum in 2011?

Observers generally consider that the al-Qaeda of today is vastly different from the organization behind 9/11.

"Al-Qaeda today poses a far different threat from that posed on September 11, 2001," according to A Threat Transformed, a report from the Center for Strategic and International Studies a Washington, D.C. think-tank. "What was once a hierarchial organization composed of Osama bin Laden and his close associates has grown to include an array of regional terrorist groups, small cells and even individuals."

Rowlands puts al-Qaeda on the cusp between those organizations that have a central, operational leadership that doesn't have a lot of control over what is going on in groups within the organization, and those that are bureaucratic in nature and would hardly miss a step if their leadership changed.

"In the immediate period, I don't think much is going to change," Rowlands says.

Longer-term effects

What will be interesting, he suggests, is the longer-term effect of bin Laden's killing, whether he becomes a martyr and if that enhances recruitment for regional groups.

And, says Rowlands, there is also the suggestion that the emergence of democratic movements in many of the typical states where al-Qaeda recruits members may be a much more significant source of decline for al-Qaeda.

Much of the evidence on terrorism suggests once a population has a legitimate venue or outlet to pursue its aspirations politically, the "terrorist option" becomes less appealing, Rowlands says.

Ironically, the revolts sweeping the Arab world may have already ensured the decline of al-Qaeda even before bin Laden's death.