If you step back and look at it logically, Nvidia are the (Current graphics leader, 'Market share') and have been for a long while. Is Nvidia really going to be hamstrung because AMD have midrange GPU's in consoles?
It's no where near that simple bud, Nvidia have buddied up with the biggest developers, they spend millions in R&D, they push PC technologies and aim directly at the enthusiast PC gamer market, you could argue they are just not interested in the console space. The next architecture is supposed to be revolutionary. Just because AMD have the console GPU contracts, won't stop PC enthusiast wanting the best hardware in their PC's, that could still well be Nvidia.
Nvidia's 'Maxwell' is going to be a monster arch, plain and simple, a lot of people might feel a lil foolish after spouting that Nvidia are simply going to roll over because AMD have console contracts.
Nvidia will push PC as it's primary platform, and lead the way with Valve on the living room OpenGL PC gaming thing, will go hand in hand with other portable devices Nvidia are working on.
Nvidia posted $1.1 Billion in revenue Q4 2013. I can't see them going anywhere..