I'd venture to say that after us, the next folks that get shown the door will be the jihadis.... I don't think the Iraqis are going to go for their nonsense, and I think the Sunnis are going to want a piece of the new order. They have a lot to lose. With luck they'll get that settled without another Saddam taking over (Sunni or Shia). Let's not forget he was a cultural thing as well; he didn't happen in a vacuum.
Once we're gone though, the next proximate threat is the extremists. Watch.