It is interesting to wonder about next generations, say the big publishers were to get together like the movie studios did with Blu-ray vs HDdvd.. They know one platform is better for the industry, just like in movies - and they may seek it. Money talks. If Activision/EA/Ubi/Taketwo gang together decide to make it a one console generation - obviously MS would be in trouble if this happened, as far as keeping a new console afloat. The GOOD remaining independent developers would have MS by the balls for exclusivity contracts - in which they'd have to still outbid Sony (and possibly a coalition of publishers against them.) There's enough money in winning for Sony to push the bidding up.
Sony has a vast array of developers that could possibly even keep the platform alive on its own, which puts them in the best position should this scenario unfold. They may make publishers partners in the profits of PS4, just like blu-ray. Sony will make their case.