It's obviously too early to make a prediction like that, but those are good points.
Anyway, I think that MS is in the best position to jump in a new generation, but it's difficult to know where the Xbox brand is strong and where it was Sony's fault for these good 360's sales.
What I want to say is that 360 did an amazing job during this generation, but for a lot of people it was the console to buy because PS3 was too expensive. In fact, in people's mind PS3 is a premium console, and 360 is not.
Probably this is only my point of view, also considering the fact that I'm Italian, so I live in a Nintendo-Sony land.
Edit: Anyway, it's impossible that 720 will sell more than PS4 and WiiU combined, maybe it will finish first next generation.