No flying saucers, no twin fuselages, no flying wings.
And there won't be because any mainstream commercial airliner will have to meet the logistical requirements of the world's airports. All the boarding terminals, baggage handling equipment, gate clearances, etc.
What good would a giant flying wing passenger aircraft be if it couldn't fit any of the world's airport boarding gates? No airline would buy it, no airport would accept it.
Even the Concorde was limited on it's flight routes because of sonic booms over urban areas. Major tech innovations bring their own problems beyond the aircraft itself.