Horace Dediu makes a strong case that both console and portable gaming are in irreversible decline. He thinks that gaming on mobile phones is disrupting the industry to the point where new gamers are not even considering the traditional console or handheld platforms.
I think he's right. Certainly, I've argued that Nintendo should have gone down a different design path with the Wii U, and the advent of the PS Vita TV shows that I was thinking in the right direction for the next generation of 'tween consoles, as peripherals of handheld gaming devices that provide extensions of capabilities at home.
I'm even more convinced that Apple is prototyping console-type experiences through Apple TV, given the recently-announced support for game controllers in iOS 7 and official APIs for sprite graphics. AirPlay streaming is already feasible for some games, though it lags a bit too much for a really solid feeling on slower wireless networks.
I've seen speculation here and there that Apple will implement games as apps on Apple TV, but I don't think that will happen precisely because mobile gaming is where the puck is going. Any Apple TV integration will be an extension of iPhone or iPad games, not a replacement for them.