As with any new console generation, the processing power contained within the shells of our systems is going to increase on a massive level. With more powerful processors and more agile graphics cards, the limits of what's capable from these boxes are going to expand beyond our basic comprehension of what's possible. When faced with the opportunity, the best way to face it is not to question how this new technology can do what we're already doing better, but what can newness can be brought to the experience through this power.
It's one thing to improve overall graphical performance - improving the complexity of our experiences visually is a given - but seeing how we can use this technology to do things previously unfathomable will be what make the jump worthwhile. Developers have an opportunity with this next generation that they have never had before; having already unlocked the ability to produce near photorealistic graphics with the current generation, what is left to do with all that extra processing capability?
If developers can realize the potential of these machines to do more than render in higher fidelity, unlocking expanded capabilities for physics, more complex artificial intelligence, and a deeper level of systems complexity that harness this power, then we'll have something on our hands that far exceeds our expectations of what gaming can be.