Just because Kurzweil's predictions from 1990 were correct doesn't mean that we can predict the future, or even that Kurzweil's predictions for the next 10 years.

Think of it this way: lots of people made predictions in 1990 about what the next 10 years will be like. (Some of the ones I remember: that Japan would take over the world, that the American government would fall, that we'd all be watching WebTV, that cars would drive themselves). Simply by chance, somebody is bound to be mostly right. That person will then get lots of media attention for having corrected predicted the last 10 years. But that doesn't mean he'll predict the next 10 years correctly.

In fact, if you look at Kurzweil's predictions from 2001 for 2009 (http://www.kurzweilai.net/meme/frame.html?main=/articles/art...):

He predicted the move to laptops from desktops. He missed the rise of smart cell phones, instead thinking that we'd be using ultrathin tablets and computers embedded in jewelry. He incorrectly predicted a move away from rotating media to solid-state memory (perhaps he was just early, solid state is likely to catch on significantly over the next 5 years - but in servers, which is the one place where he thought it wouldn't catch on). He correctly predicted the rise of wireless. He was dead wrong about the usage of speech recognition technology, which is still too unreliable to recognize more than a few keywords.

He missed the rise of international terrorism as a new geopolitical power. He missed the emergence of the U.S. as an aggressor nation that actively declares war on other nations (in fact, he predicted that national wars likely wouldn't exist), but correctly predicted that the U.S. would remain the dominant military power.

He incorrectly predicted continued economic growth, particularly in the stock market, which is now below where it was in 2001. Economists still do not believe price deflation is a good thing. The U.S. remains an economic leader, but its leadership has declined somewhat. He correctly predicted the rise of China. He missed the emergence of the EBay/Paypal/Adwords economy, where perhaps a million or more people can now make their living off selling niche products online. He did predict the rise of online transactions, however. He completely missed the growth of social networking as an important cultural force. He incorrectly predicted the development of intelligent assistants, which never caught on. He correctly predicted the download economy, where you pay for an information product and then download it directly instead of accepting a physical copy.

If you were to meta-analyze these predictions, there's a pattern that emerges. Those predictions that took an emerging technology that had already caught on with mainstream users and extrapolated it out to pervasiveness tended to come true (laptops, faster computers, wireless, China). Those predictions that took an emerging technology still in the R&D stage and assumed it would catch on usually failed (solid state storage, speech recognition, intelligent assistants). And then inflection points that came out of nowhere obviously were never predicted at all (social networking, AdWords, terrorism, U.S. aggression).

The thing is - there are always those black swan events that come out of nowhere. And they tend to be where fortunes are made. Everyone expected laptops to get cheaper, faster, and lighter in 2001, so that was already priced into their market value. Nobody expected that a good portion of our social lives would consist of broadcasting 140 character text messages.