Before history gets too rewritten in this thread, I believe the initial concept for the MRA4 was limited to new, more fuel efficient GE engines, modern avionics/glass cockpit and new Missions Systems in the back. Amongst the (intended) major benefits were lower aircrew and groundcrew retraining costs, use of existing infrastructure and logistics chains.
That concept went into the negotiations with MOD and the new, unnecessary wing/engine combination emerged, in response I understand to phrases such as "must have Rolls Royce engines" and "what about wing fatigue?" BAES had eliminated fatigue as an issue and documented its reasoning at the very start of the process.
EAP