US doesn't need Boeing to pressure Airbus on the price. This same periodical suggested last week that Airbus was selling the A350XWB-800 and -900 for the same discounted price as the 787-8 and was also giving free planes if you bought in lots of 100. If true, that should be more then sufficient for US to stick with it, no matter when it enters service.
If US does go to the 787, it may very well be the case that the 787 is now a "known entity", even if #001 has yet to be assembled, much less take to the skies and completed her test and performance benchmarking regimen.
And this would not be because of blind faith in Boeing "always under-promising and over-delivering". If that was the case, we'd see a lot more 767-400ER and 747-8I orders on the books right now...
No, it is because Boeing has proven to the satisfaction of almost 50 carriers sufficient performance simulations for them to order almost 600. Either that or Boeing has given every one of them carte-blanche
to sue them up the bum or cancel without penalty if the 787 isn't everything those simulations claim. And while that might very well be true for some of these later orders, remember many of them were placed before the A388 program encountered rocks and shoals...
is the biggest current threat to the A350XWB. "A bird on the tarmac is worth two on the drawing board", so to speak.
Yet, before Boeing Boosters crow to loudly, temper that enthusiasm with the knowledge that five years or so from now, Airbus will be in the same position with the A350XWB vs. Y3.