Interesting prediction considering we don't know everything about what neurons do. There are folks who argue that it is the interconnections rather than the neurons that are key. The interconnections change with learning, and we don't have a good model for this process.
Kurtzweil does a lot of handwaving on the biology side, but he claims that computers at least should have the capability to exactly simulate the brain.
By the year 2100, everyone will have ported out of their carbon based forms. We will all be converted to software. The creationists will love it.