This is an interesting article/white paper from a few years back.
It seems that the A3xx is inevitable and the 747x is losing and may even never be built. That is the feeling I'm getting. Would any company who has already pledged to invest in the A3xx ever consider purchasing a 747x Stretch? It seems unlikely, otherwise, why would they not have gone with the 747x in the first place.
Anyway, it seems that if Boeing had gone ahead with the 747-500x and 747-600x earler in the 90s as they originally intended, they might have gotten airlines on board already and the A3xx might never have had a chance to take root. It seems that by cancelling the 747-500x and 747-600x, Boeing opened the door for the A3xx. It seems like it may have been a fatal mistake as now the A3xx is going to eclipse the 747-400 as the most prestigious and well known commercial aircraft in the air. Your thoughts on this?