Whenever I see these Kurzweil naysayer articles, I always feel like they are overly pessimistic, or short-sighted. Just because problems seem insurmountable now, doesn't mean that they will be in a few years. People always seem to forget about the exponential growth of information technology. If you look at an insurmountable problem in the context of today's technology and speed of discover, then yeah, it will be tough to believe that we'll have sentient machines any time soon. But please do not forget that tomorrows technology will be exponentially better, faster, stronger than what we have today. In five years, the problems outlined in the article may seem like child's play.