There was a very interesting on Flight Global yesterday regarding US Airways requesting that Airbus give the A321NEO enough range do do transatlantic in order to directly replace their 757 fleet.
It really makes a great deal of sense. US Airways stated that they can't get their hands on enough 757s now with the likes of UPS and DHL buying up every aircraft going. I've always felt that Boeing closed the 757 production line too early as a knee jerk reaction to the general downturn in aircraft production at the time. I very much doubt the line could be reopened now, but I dare say if it were then Boeing would still be receiving new orders for the 75.