According to
this story there are at least 100 different 'insurgent' groups in Iraq.
Zarqawi was the front-man of the _foreign_ insurgency in Iraq. Now that's only like 10% of the insurgents there according to some retired general I just heard on the radio, but it was the most organized group, he said.
I'd bet this will reduce the number of foreign fighters coming into Iraq. And it probably means that group calling itself 'Al Queda in Iraq' is going to be very disorganized for a while.