I agree that an Unfriendly AI could be a complete disaster for the human race. However, I really don't expect to see an AI that goes FOOM during my lifetime. To be frank, I think I'm far more likely to be killed by a civilization-threatening natural disaster, such as an asteroid impact, supervolcano eruption, or megatsunami, than by an Unfriendly AI. As far as I'm concerned, worrying about Unfriendly AI today is like worrying about global warming in 1862, shortly after people began producing fuel from petroleum. Yes, it's a real problem that will have to be solved - but the people alive today aren't going to be the ones that solve it.