One would hope this could be done in 3 days, but I seriously doubt it.
Saddam will not give up without a fight. His back is to the wall and he knows he is a dead man if he loses. He will lose, but will still put up a last ditch fight. And don't forget, there are probably a lot of fanatical Al Queada (sp) in the country and others who know they will be dealt with harshly when caught.
Then, the "winning" factions will begin duking it out....