I don't doubt there will be reprisals against members of the current regime. Expect it. But I don't see a civil war between the Kurds and the Shiites. The new leadership group of each constituancy will have a huge incentive to stablize the region, gain the trust of their people, etc. If they want to prosper economically and politically, it will be in their own best interest to behave.
You must understand that the vision apparently put forth by Bay Buchannan scares the hell out of the rest of the region. Free elections, democracy, growth in per capita income/a prospering citizenship, etc. Of course the Saudi Royal family, the thugs in Syria, etc. aren't very excited about this.
Turkey is also unsure about the prospects of a free "Kurdish state" on their southern border. Also could be concerned about the prospects of another secular democracy in the region.
