the technology is very important but it's getting the infrastructure to go with that technology which would radically change on the airport level as well. it would change the fuel that implies an entire infrastructure to bring that fuel into the airport as well. they'll also do away with windows for passengers. the wing blending into the cabin means you just can't have them. instead, there's a suggestion that passengers will have virtual screens, which should make up for the lack of a real view. well, that's where hybrid technologies come in — aircraft which look like a conventional airliner gas engines on the wings but with an additional electric fan behind the tail. this is a concept known as boundary layer ingestion.