The 787, all three of them, possibly four (787-10), are not replacements for the 757-200. The 787-800, has a relatively close capacity of 210 to 250, however, in three classes, and its range is vastly longer than that of the 757. The replacement and direct competitor to the A321, as a replacement to the 757, is the 737-900 ER
, its capacity, size, and range is very similar, yet the aircraft is more economical, makes sense does it not?
When comparing the 787 to the 767, the 787-3, seeming to be an A330 competitor, is actually quite similar to the 767. The 767-400ER, is the 787 of comercial service today, without a doubt, the 787 will retire this (the aircraft are too similar). The main difference between the two aircraft is the range and capacity characteristics. Boeing has sat the 787 in this order, where capacity and range are directly proportional 767<787<777, this is to say the 767 has less range and capacity than the 787, and the 777 has a higher capacity, and the range is most similar to that of the 787, though the 777's capacity compensates for the shorter ranges, with the exception of the 777-200LR, of which has a capacity of 301, and a range of 9420.
The 777-200LR is extremely superior compared to other aircraft. I expect this to sell very well in the future with North American airlines and Chinese airlines, as China's expanding economy should increase business between the two powers immmensely. The LR
should pair up the cities of North America and Asia, more effectively than any other aircraft, including the A340-500/600, (my philosophy is that two engines are easier to maintain, and more efficient(less drag) than four engines, something the airlines will take into account, the smart airlines). Its high sales should be based on the original 777's performances and safety record, remember that air france incident in canada with the A340, well at least everyone survived.
Back to the issue at hand.
The guy who came up with the 787 for boeing was a genius, because this is how the story will go:
Airlines buy A380, yeah, good at first. then! Over the years, because, its huge and can only go to big airports, airport landing fees, and taxes, will rise. Airlines won't like this, such that 70% of passengers on an A380 are'nt making frankfurt, paris, or Beijing their final destination, they're actually going to board a 737 to munich or bordeaux after their long flight. So fly that 70% with a smaller more convenient aircraft, the 787, landing, airport fees will be cheaper, and will be more effective over time, because you can now land at bordeaux, and munich, with increasing passenger demand over time.
So what I'm saying is, the 787, will link point to point, rather than large unsustainable, unbearably inconvenient for passenger connecting major world hubs.
Yet, time will tell, and airlines will choose aircraft for different reasons, e.g. why qatar has ordered 60 hypethetical aircraft from airbus drawn on some paper, when boeing has something a lot closer to reality. I think they call that airbus aircraft the Airbus A3787, not that airbus have gone and directly copied the 787, just like they didn't copy the 737's winglets for their A320's. So there we go.
Work Hard/Fly Right.