Considering the 680 is a 1080p monster and next gen systems use last gen video architectures, probably.
Wrong, completely wrong.
Think of this case:
The current consoles use 1900 or 7900 class GPUs single core. And to play maxed out at 1080p without AA some games require 6970 or above grade GPUs, or at least 6950 grade GPUs to average over 60-70+ FPS.
Considering a 6670 is about twice as fast as those GPUs and CF means 4x times as fast because this a console which means perfect scaling. That means we will easily need something 4x times as powerful as a 6970 to play perfectly fine, not Quad CF 6970 but something which gives 4x FPS of 6970.
The 680 doesn't even give 2 times the FPS or at most two times the FPS.
So you will probably need something at least twice as fast, something faster than the big kepler and faster than 8970.
But till the time next gen consoles come out, you are perfectly fine at 1080p. So that period is going to last a good 1-2 years or so. After 2 years it may become tricky.
But you need to consider that not each game is a port, Alan Wake for instance is an exceptional port and is well optimized. To play such games maxed out at 1080p without AA, you need to upgrade from high end to high end once every 1.5-2 years.