The issue is can Boeing or Airbus come with a brand new airplane in 2017 time period or will they essentially keep the current airframe and just change the engines to gain the fuel efficiency?
And I wonder if Boeing have a game changer up their sleeves. Something that will prossibly not just be about fuel burn, but perhaps about huge efficiencies in maintenance/repair with regard to flexible schedules, spares inventory management, flexibility in lifing cmponents depending on the type of operation, etc. Perhaps somebody who understands this side of things has some ideas.