Remember, the ME political mindset isn't as advanced/cynical as the West's is.
This is a political grandstand move intended to convince those with insurgent/terrorist tendencies that the government *isn't* the puppet state that the Islamonazis are saying it is, nothing more. Otherwise, they would be making real demands for us to leave - they *know* we're propping them up until they can stand on their own. And until they can take care of their 'personnel problems' on their own.
If we (and they) can pull this off, this will be the end of the Middle East as we know it.
I think it's also a way of undermining the charge that the US is there to steal the oil, or use Iraq as a base to attack Muslims in the Middle East. The US Says, hey let's go six months without a car bomb, a kidnapping, cops executing people in the middle of the street, political executions and we'll be gone.
Bingo. They are pandering to the Sunni insurgents.