The only positive that I can think of is that it enables the American public to consider what gains they have from this war.
It is becoming increasingly clear that there are really none.

If it brings into question whether democracy can be institued in a foreign land by military occupation, then maybe this is something.

The problem basically as I see it is this. The Insurgents are increasingly the Iraqi people. The common unifying "enemy" are American soldiers. Bremmer's dictates will not be followed. To enforce a government (nation building) by another country is a prescription for dictatorship. Alawi is already being called by some a "strong man". (Last use of the term was for Noriega who the US initially supported).

If this picture is made clear to Americans, then that is a positive.

Frank