if tube and wings design is to change, i think it will be some less radical changes than flying wing, more along the lines of transitioning the tube into the lifting body, while may be not the full way along the Burnelli http://www.burnelliaircraft.com/wp/ , instead more like the modern version https://en.wikipedia.org/wiki/Aurora_D8 :

"The aircraft is designed to be over 50% more fuel efficient[1] compared to aircraft currently under production."