Glenn Harlan Reynolds interviews Ray Kurzweil, who generically answers my objection to his forecasts.

to achieve the software designs, we need to reverse-engineer the human brain. Here, progress is far greater than most people realize. The spatial and temporal (time) resolution of brain scanning is also progressing at an exponential rate, roughly doubling each year, like most everything else having to do with information. Just recently, scanning tools can see individual interneuronal connections, and watch them fire in real time. Already, we have mathematical models and simulations of a couple dozen regions of the brain, including the cerebellum, which comprises more than half the neurons in the brain…By the mid 2020s, it’s conservative to conclude that we will have effective models for all of the brain.

So at this point, we’ll have a full understanding of the methods of the human brain, which will expand the toolkit of techniques we can apply to create artificial intelligence. We will then be able to create nonbiological systems that match human intelligence in the ways that humans are now superior, for example, our pattern- recognition abilities. These superintelligent computers will also be able to do things we are not able to do, such as share knowledge and skills at electronic speeds.

The interview is wide-ranging and interesting.