This is has been the law in Alaska for a long time, but it's new for Michigan. According to the Michigan Supreme Court's decision in People v. Rea, a person can be convicted of OWI for operating a vehicle in their driveway. The law doesn't seem as broad as Alaska's yet and the Court certainly seemed to give weight to the driver's intent to get out on the road. Attempted OWI, anyone? The Free Press covered the decision here and the opinion is available here.