The 747 still looks unique though, and is likely to continue to do so for decades. It is, quite simply, an iconic design. It has been around for ages and in no way looks dated.
Remember that the 747 first enterd use as Air Force One in 1990, some 20-odd years after it entered passenger service. Anything 'cutting edge' will likely have to see several years of trouble-free operation until adopted as AF1. The Boeing 707 served as an AF1 from '62 to '01, hardly cutting edge, or indeed uniquely styled - though perhaps iconic, for its latter years. I don't look at a 787 or A380 and think cutting edge either - both look entirely conventional in fact. Sure, the A380 is big and the 787 has bendy wings, but neither makes them cutting edge visually - and I don't think the general public of any nation will give two hoots about advanced
internal design or anything else.
There are more advanced aerodynamic proposals in (general) development - I'm not referring to enlarged/reduced blueprints of tubes with wings here. Anything 'cutting edge' will likely have to see several years of trouble-free operation until adopted as AF1. And it isn't really that aerodynamics have advanced, it's that material technology has, thus making them viable to build.
Boeing's '
Yellowstone' is divided in to three projects. Y3 is supposed to lead to a 747 and 777-300 replacement. Might see one of these as AF1 sometime (these are all NASA concepts, I think) probably over 50 years away though. I dare say tdracer has access to a great deal more information.
