There is an interesting article over at Tech Central Station concerning what shape a new Iraq should take. Carroll Andrew Morse tries to take a more democratic approach to the situation instead of forcing a one-state solution.
The basic idea is that Iraq will be broken in 30 or more provinces. Each of these provinces would be allowed to build a local government, and when a province has done that, it will be promoted and allowed to rule themselves. As more provinces progress, they would be allowed to join with other self-governing provinces and create sovereign states. These states could even take in provinces that newly graduated or join with other states.
This allows the people of Iraq to draw their own boundries, instead of trying to force everybody into a single solution that is acceptable to none. It also creates a way to allow parts of Iraq to progrss at their own pace. If some provinces remain hostile, that will not hold back the other provinces. And it would allow troops to move away from those areas that built their own self-governing and self-policing structures and into hot-spots, concentrating troop force where needed.
In the end, if the poeple of Iraq want to be a single state, they can be a single state, but if the Arab areas do not get along with the Kurdish areas, then they don't have to be joined. The problem with British partitioning of the sub-continent was that it wasn't democratic. It was dictated a top-down geography and that created the Kashmir problem.
The author calls it "Partition by Popular Sovereignty" and it is presented in The Case for Partitioning Iraq. It sounds interesting, and theoretically could be a good idea. However, politics would definitely block anything like it. I don't think it would be blocked by too many Iraqis, but Turkey and Iran would go nuts over the idea.