The NYTimes has an opinion piece by Frederick Barton and Bathsheba Crocker from the Post-Conflict Reconstruction Project at the Center for Strategic and International Studies. They suggest holding a referendum where we ask the Iraqis themselves whether they want the U.S. to leave immediately, or not.
I like that idea! One additional spin they don't mention is that you could hold the referendum along with the parliamentary elections. It would give the insurgents who oppose the elections a reason to boost voter turnout.