Tankengine,
I assume that is the rumour referred to here:
Aviation Business: B787 headed for a different role in Qantas?
Certainly an interesting rumour. Would Boeing really manufacture different engine pylons (assume it is already different between the GE GEnx and RR Trent 1000) - though the one of the requirements of swiss cheese design was to standardise parts so you don't get the wrong part on the wrong aircraft