As Silicon Valley matures, I think age bias will become less prevalent. I think there will be an inflection point where novelty is going to have to give way to quality. Facebook is illustrative. Facebook is exactly what you'd expect to get if you hired a bunch of recent college graduates to build something: creative, but otherwise utter crap. It's not what you would get if you hired a team of seasoned professionals to build a product with well-defined requirements. At some point, I think in the near future, you'll see Facebook (and the other companies like it) transition from the former into the latter.