Michael should have been left for dead after part 2.
I'm sorry to say that I don't think that'll ever happen. The character has brought the company too much money and, while they're marketing Halloween II as the last one, I doubt that it'll be the end. Rob Zombie, for example, had said he felt his take on the character was over after Halloween, but the producers told him they were going to make another with or without his help so he signed on to do part 2.
I honestly expect in about two years there'll be Halloween 3.