Hes right about generation length. Think about gaming right now. Think about playing, say, battlefield bad company 2 on your 360 or ps3. what are the differences between that, and a 1200$ PC? Little. Of course the pc version is superior in every way, but the only real noticable thing for consumers is resolution. You wont see new consoles for a long time. Any new breakthroughs will be too expensive.
Console generations for the next while are going to be based on periferals. it's only nintendo that needs to catch up. Sony's PS3 is basically equal to their next gen system.