Airbus is NOT going to do an out-of-family standalone product with it's own production line (no possibilty for customers to switch variants before delivery).
Toffeez, Airbus and Boeing do it all the time. A340-500/600, A330F, MRTT, 77ER/NG/i, A310, 764 etc. As shown earlier it could be a regular subseries, A321XR, A322XR. It would mean additional sales on top of A320 series sales.
FlightpathOBN, I never thought/ said that is a 787. First time I see an 787F cross section though. Biggest hurdle IMO would be carving a big cargo door and strenghtening the surround all composite structure. Adding structure probably isn't as easy as metals..
USMCProbe, lets not narrow this to a 757 replacement. As I showed earlier there a big replacement market, 767-200, 767-300, 757-200, 757-300, A300, A310, Tu154 and demographics show billions of people live within 4000NM of each other.
photo by icarus
Still we could ask the hypothetical question; if the 757 was >10% lighter, used 25% less fuel, had 100% cockpit commonality with >7000 other aircraft in service and on order, was 3 times quieter, got a widely used containerized cargo system, wider cabin, and the earth was guaranteed covered with existing assembly lines, MRO, crew, training infrastructure for the next 25 years, would it be a feasible 757?
I remember specifying the NEO, rewinged stretchedE195, MAX and Ecoliner many years ago and everyone balked. Its just logical evolutionairy upgrades.