If there's any truth to pg's claim that the paradigm is shifting and that talented people are increasingly likely to start their own thing than go work for a boss (and personally, I believe there is), then one would expect just the opposite of what you assume: more wealth should be created this way in the next 5 years than in the previous 5, because more value will be. And the productivity delta between startups and large companies will grow even faster, since the latter will be increasingly starved for new talent.

Edit: one might also expect current economic conditions to accelerate this process, since downturns are harder on inefficient players than efficient ones. It occurred to me the other day that for this reason, downturns are a healthy part of the economic system, kind of like forest fires in ecosystems.