"In my most recent novel, Rollback, published in 2007, I predicted that humanoid would be common within 40 years," says Robert Sawyer. "I'd revise that figure way downward now. Having been to recently, and looking at what's coming out of Japan, I suspect we'll see them much sooner than that. People want household help; people hate anything that makes them conscious of class and past injustices. Robots are the answer, and they'll be here soon."

Nancy Kress wouldn't change anything. "The short-term predictions have proved true, and the long-term ones can't yet be verified or disproven. Literary safety in avoiding the mid-range timescale!"

What advice do you have for writers-or technologists-trying to make five to twenty year predictions and forecasts?

"The standard advice is to be aggressive in your predictions; there's this notion that the future always comes faster than you think it will," suggests Robert Sawyer.

"But, actually, I think a lot of us underestimated social inertia," he adds. "Most of us predicted a secular 21st century, and it's anything but that. The world is like a person: It doesn't change as it gets older. Rather, it simply becomes more obviously what it always was. People always liked having phones and portable music, but most people never wanted to lug a camera, or an ebook reader, or a around. The future is adding functionality to those things we've already admitted into our lives, not trying to convince people they need new categories of things; the iPhone-the all-in-one device that is, first and foremost, something familiar-is the correct paradigm."