I think there will almost certainly be at least 2 NFOs in the back of the new plane; big-wing airplanes with large missions have long OTJ periods for new NFOs, just as there's a 3P-2P-PPC progression. Way too much to learn it all in the RAG. He/she will probably be called the NAV whether he actually does much navigation or not, though the job will probably be more akin to an Assistant TACCO.
As for the training pipeline, for pilots, my money is they'll expand the Tinker E-6 program with some trainer 737s, and shrink VT-31/35 just to keep the Herk/Hummer/Heavies pipelines alive. As long as the Nav is kicking in the money, I don't think the AF will have a problem with expansion.
For NFOs, I think they'll go to a program like what they do for E-2s now - send them on to the RAG after Intermediate and have them get winged there. I hear rumors they want to do that for the P-3 community anyway.
As for what they'll call it... since the 737 is already in the fleet as the C-40, maybe the PC-40? Nah, probably the P-8. "New airplane" and all.