Good games will resolve a lot of things. But they also need patience, actual success would probably only happen in the next cycle.
I think that if they have had a proper follow-up to the 360. The xbone would have been proper console, with a focus on gaming performance, be just a bit more powerful than the ps4, or maybe if Sony had shipped the PS4 with 4GB of RAM. They would have taken over Sony in the last generation, people still remembered the early 360 days and associated MS with the good part of that, a good number of gamers also wanted the better performance in third party games (associated with Xbox at this point).
So the worst happened for Xbox:
- they didn't show up for hardcore early adopters
- Sony did pretty good with the ps4 (other than the fan noise).. also, Sony gained a lot of good will by shipping great 1st party games on the ps3, that gave them some momentum
If MS had a good underdog end of generation they could be in a position to gain the upper hand for the next one.
Obviously this Xbox fan wet dream assumes Sony does nothing to keep their clients and that MS does everything just right