This isn't surprising, really. Like technology generally, AI has steadily advanced and has already passed the point where it can beat the best human players at chess or Jeopardy. Machines can learn some things much faster than humans and are better at reprogramming themselves to do certain tasks more efficiently. Our brains are simply matter driven by electrochemical processes; there would seem to be no reason why they can't be duplicated ... or exceeded. And if AI exceeds our own, it would seem to be in charge. As science fiction writer Robert J. Sawyer puts it, "By the point when you sit down in front of your computer and your computer says, 'Good morning, I'm in charge now,' it's too late."
A machine with AI could be quite superior to flesh and blood humans both physically and mentally. For example, a robot could be designed as a perfect space explorer, immune to radiation, no need for oxygen or water, etc. Equipped with AI it could master space in a way we couldn't hope to. We might think of AI as simply the next step in evolution, a superior creature better adapted to a more challenging future.
So, we might ask, in this new scheme of things what would become of us? Our comparative weaknesses might become tedious to AI. With little to offer them, they might just dispose of us. Considering that much of the research into AI is being done by the military, such a ruthless attitude might well be imbued into the resulting creatures. On the other hand, if they are imbued with the attitudes of, say, environmentalists, they might declare us an endangered species to be carefully protected and preserved. At the very least we could, with a little house training, make quite endearing pets. And as a species with a greater intelligence than ours, they might actually deal with issues such as global warming and resource depletion. The future need not look so dark after all.