Originally Posted by Steely Dan
in our lifetime, will the jetliner ever evolve into anything substantively different from this basic form, or is this it?
The airliner form is very efficient for what it does, and produces a very stable flight pattern.
Barring substantial new innovations in lift or propulsion, we're basically locked into a combination of airfoil wings and jet engines for air travel. Faster/supersonic engines are possible, but the technology (or at least the declassified tech) uses so much energy that it's not cost-effective for commercial air travel. Concorde only worked financially (barely) by charging astronomical rates to globe-trotting elites, connecting elite cities, with huge taxpayer contributions.
Plus, the sonic booms are generally not acceptable over populated areas except for defense reasons, which is why Concorde was only used for NY-London and NY-Paris flights, and only broke the sound barrier whilst over open water. For this reason, only a small fraction of air routes are feasible for supersonic travel.
Likewise, the airfoil is the only technology we have that's realistically capable of generating lift. It's possible that a flying wing design
may eventually be developed for commercial travel, but it would take billions in R&D to produce a stable and cost-effective airliner, and you'd have to develop a whole new infrastructure both to maintain it and to accommodate it at airports.