The recent post on nuclear power assumed a number of future improvements, in areas like commercialization of breeder reactors, greater uranium mining and processing efficiency, secure waste transport and disposal options, lowered plant decommissioning costs, and electrification of the industrial and transportation sectors. If it's okay to assume speculative improvements for nuclear power then why not for cellulosic ethanol?

But I am playing devil's advocate. Speculating on future trends is what entrepreneurs are in business to do. Governments shouldn't bet on one horse when there's a whole field of promising contenders and new breakthroughs are announced every month. Better they should all compete without subsidies or preferential treatment.

I certainly didn't say it was OK to assume advances.  On the other hand, I think research, and piloting these things, is important.  That's the only way you find out if you have a chicken.