Paul Allen knows a thing or two about computers; he built the company that is the definition of the operating system for modern PCs.
He's as optimistic about the power of technology and its ability to shape culture as anyone can be but, like us, he is more skeptical that it will translate into actual human evolution. Like us, he notes that Ray Kurzweil's Law of Accelerating Returns is just an optimistic black box based on a 'law', like Moore's Law, that is not a law at all, it is simply matching past topology to an idea and extrapolating it into the future.
Allen's piece in Technology Review is more philosophical, he doesn't get into the stuff I have about the physics-induced train wreck rushing at us, which stunts the ability of processors to shrink, or the notion that if something is redundant in the brain it can be compressed like an .mp3 song and it will make no difference in cognition.
He and co-author Mark Greaves do a nice analysis of The Complexity Brake, where the complexity of a topic (like the brain) causes insight to slow down, almost like speed halts the closer we get to the speed of light.
Paul Allen: The Singularity Isn't Near by Paul Allen and Mark Greaves, Technology Review
Microsoft Co-Founder Paul Allen Is Not Buying The Singularity