The only reason boeing is looking at the 747x is because airbus is building the a3xx. They would be crazy to miss this opportunity! They cant let airbus have the WHOLE market on such a big jet! In a nutshell, what they are thinking is "If we dont do something to counteract the a3xx, we will be losing alot of money". Boeing was pressed into developing the 747x because of airbus. A while back, boeing shelved this project sighting that "this much capacity was not needed in the current economy". The main reason that this aircraft is being developed is to compete with airbus and to keep the #1 spot at the top.