Yeah, but regime change in Iraq is only one step in the war against the Islamists.
The consequence of destroying Saddam is destabilization of Iran, Saudi, and others in the Middle East, as well as impeding money flows and arms to the PA and Pakistan.
Saddam is pivotal but personally incidental to the larger war.
After Iraq, down goes Iran, then massive pressure on the Saudis and Pakistanis, and perhaps Pakistan will even lose its nukes (whoops).
N. Korea will be dealt with in good time.