What I think about machines that think is that we are all missing the point still. The true transforming genius of human intelligence is not individual thinking at all but collective, collaborative and distributed intelligence—the fact that (as Leonard Reed pointed out) it takes thousands of different people to make a pencil, not one of whom knows how to make a pencil. What transformed the human race into a world-dominating technium was not some change in human heads, but a change between them: the invention of exchange and specialisation. It was a network effect.
We really have no idea what dolphins or octopi or crows could achieve if their brains were networked in the same way. Conversely, if human beings had remained largely autonomous individuals they would have remained rare hunter-gatherers at the mercy of their environments as the huge-brained Neanderthals indeed did right to the end. What transformed human intelligence was the connecting up of human brains into networks by the magic of division of labour, a feat first achieved on a small scale in Africa from around 300,000 years ago and then with gathering speed in the last few thousand years.
That is why the AI achievements of computers were disappointingly limited when they were single machines, but as soon as the Internet came along remarkable things began to happen. The place that machine intelligence will make the most difference is among the machines, not within the machines. It's already clear that the Internet is the true machine intelligence. In the future, network phenomena like block-chains, the technology behind crypto-currencies, may be the route to the most radical examples of machine intelligence.