All I can say is "insufficient data". All we can say is that Nintendo will look for what kind of improvement would increase the customer value the most while costng little to implement. They may know what that is, we don't. If a sustaining innovation ("Wii but better") is a good idea they'd do that (but the competition would arrive at the same conclusion provided they could ever wrap their heads around proper "casual" software). I'm not sure it'll be a disruption though, a disruption means scaling the traditional values back to save costs, that only make sense when the values have overshot the customer and scaling down won't have much of a negative effect. I think when you don't scale anything down and just find new values to boost without abandoning the old ones that's "plain" Blue Ocean.
As for going with PS360 level graphics, the problem is still that a game making use of those costs BIG money to make, at least using core design philosophies. You'll probably see developers make stuff that doesn't look as pretty as the PS360 stuff now or go out of business. Of course not as pretty is not the same as not using the system power, something like EDF can use absurd amounts of system power with art that still looks like it was really cheap to make. It'll just be hard to get the right philosophies hammered into the heads that get to make the decisions for most companies.