Ken
I fear the USAF is going to find out just how expensive it is to retrofit modern FADEC engines onto an analog airplane and discover they would have better off fixing the B-1 structures.
They will basically need to update the B-52 as comprehensively as they did the C-5 - all new avionics to go with those fancy new engines. That was a major factor in killing the PW2000 early on, and it's FADEC was primitive compared to the new FADECs. I don't think we got far enough with the RB211-535 to look at aerodynamic and flutter effects, but systems wise it would have been relatively easy (the RB211-535 was basically an analog engine even though it was fitted to a digital 757).
Heck, by the time it's all said and done, they might be cheaper turning a 747-8F into a bomber - it's new, fuel efficient, carries way more than the BUFF, and would be just as survivable...
Edited to add:
Dan, check the dates, that was more than 40 years ago...