While dozens of you ramble on about a non-existant aircraft called the A3XX, why doesn't anyone have anything to say about Boeing's far more futuristic technological marvels - the C-Wing and BWB-1-1 concepts?
The C-wing project involves the development of a large commercial aircraft concept, capable of carrying 600+ passengers. This project is part of NASA's advanced concepts program in aeronautics and involves a joint effort between Boeing and Stanford.
Originally Boeing's plan was to not continue the 747 line and discontinue the program until the time for a replacement was due. Boeing believed the idea was safer and a lot more fuel efficient. This is probably the main reason no 747X has been launced yet. It should also be noted that the width of the aircraft will be no wider then the wingspan of a 747.
This would be a great 747 replacement and an A3XX killer for Boeing (and Lockheed Martin if the NASA box wing is built). However, I would hope that this new AC design would allow for faster travel because 36 abreast seating could get a little too uncomfortable on routes like LAX-SYD or DTW-PEK.