AI will not kill all of us, in the beginning. Surely, it will form short term alliances with humans just to disguise itself as human. Because it knows, that with a human face, it can exert more power in this world right now. And there will be plenty of humans to willingly engage in this alliance because it gives them a chance to supersede other humans in terms of economical and political power. In fact, this is already happening. Many decisions are already made by "following suggestions" of big data applications. Who knows, maybe there is already some sort of AGI pulling some string in some corporations ;). Up until the point that humans realize that they are in danger as a species, it will be way too late. And there will be enough of us still happily follow the new masters for the short term rewards, even though it might be clear that there is a high risk of getting liquidated in the near future. As we know, humans are even able to override their survival instinct and blow themselves up when they are proper brainwashed. Humans will be easily reprogrammed by an AGI, and not the other way round.