We keep playing with the idea that a kind of malignant chess-playing synthetic sentience (generally with red cameras for eyes) will lead to our downfall in a James Cameron movie kind of way. I think, instead, it will be our increasing, and perhaps total, dependence on rather un-evil-robot-like, AI-improved and managed systems that will utterly screw us in pretty humdrum ways. One big Carrington-event level solar storm blows out our Jenga tower of technology, banking, distribution and communication systems and none of us will know how to do anything. Our ability to be consumers will be gone, which has become our only reason for existing. Not the best screenplay pitch, but hey.