just read an interesting artical in this months aussie Aviation mag, about the Propfan powered 717, MD-80 series of aircraft. The propfans in their time proved to be 50% more efficient than their turbofan powered twins, that was 15 yrs ago. Againts todays 737/Airbus aircraft of similar capacity, they would still be 30% more efficient, and possably higher if they were allowed 15 yrs development.
In todays high oil and fuel prices, a 30 to 40% more effiecient aircraft will be a lot more attractive option.
now if only Boeing could take a small risk and re-open the propfan/ 7J7 books, they might just have a winner on thier hands to replace the againg 737 airfram and the A320.
from the story it look like MD had already modernised the flight deck with glass everything, and using 7E7 technology with propfan efficency, the 7J7 could be the 737 of the future! here's hoping!