It really depends on the strategies each of the companies uses to produce their next console ...
If the generation becomes an "Evolutionary" upgrade on the current generation Nintendo will have a massive advantage because of their position in this generation. If Sony, Microsoft or Nintendo try to push a more "Revolutionary" upgrade it could the market will change in unpredictable manner (at this point in time); it is possible that a "Revolutionary" upgrade could be successful like the Wii, or a failure like the Virtual Boy.







