Boeing has two different flight bags of technology. One is the step bag of advances for the current 777-300ER, the other is the 787 Bag of Technology for the 777X. Currently Boeing is plussing out the 777-300ER with refinements on its engines and improvement for its customers interiors. It cannot change the humidity or the approximate 8,000 foot air pressure in the cabin, nor it may not change that feature for its up and coming 777X design. But it will bring forward many improvements on the 777-300ER in the interim period before the 777X arrives. This is a gap filling effort of keeping the 777-300ER in-play for building 100 777 types a year going with both freight and passenger services.
If the 777-300ER remains formidable to Airbus' A350 introduction, As it can do so with vastly improved interiors and amenities for its passengers. It will fly efficiently as always, against the A350 hopes. Customers who have gained profitability with the current 777 will have an enhanced version that will carry forward until 2020. Airbus is locked-in production with serving all its customers with orders for the A350. Boeing can cherry pick the market offering current gratification of delivery soon after purchasing documents rather than later.
Order a A350 today it will arrive in 2020 when the 777X arrives. Order a 777-300ER or 200 today it arrives in the years 2016 or 2017 and will fly for three more years without any competition but from Boeing itself. Airbus will after-all have to ramp up production during those first three years of production (2015,2016,2017) for the A350. By 2020 they (Airbus) maybe in sync with its customers for delivery, by producing 70 A350 aircraft a year. Meanwhile back at Everett, Wa. , Boeing will have been relentless with both programs, the 777-300 enhanced and the 777X using the 787 play book bag of technology. That 777X bag which will never see daylight for the 300ER lists: laminar flow technology, plastic flight surfaces, and applicable 787 technology found throughout the airframe. The 77X will havea host of other innovations which will make the 777X more efficient than the A350 twins, the dash -900 and dash 1000. I didn't mention the newest in engine technology for the 777X.
However, by slight of hand Airbus adopts the A330neo into the A350 family of aircraft so it may battle the 787. The A350 already lacks 787 technology, where the A330 NEO will suffer a blight of technology when compared to the 787 benchmarks. Customers get to chose which airplane. Many will try the A330 off the bargain shelf to make up for inefficiencies against the 787. They will have some gratification on its choice, but it will play out later on at the ticket window.
A concluding thought for Boeing's two flight bag approach. One is for the 777-300ER and the other is for the 777X, is an indication that Boeing is taking serious everything in the market place, and is leaving no stone unturned. The old Boeing would have dismissed any threats from Airbus and moved ahead without regard to the market. Things have changed since those days and Boeing is attacking the market with pleasing options other than just calling something NEO.