Nvidia is busily building the future of gpus, with speeds up to ten times that of the previous Maxwell generation. Pascal is superfast, using all new high bandwidth memory, and so on. Volta is even faster than that.
AMD has similar high bandwidth memory gpus coming.
But is there really any reason for these gpu's to be built? 1080p is the highest resolution the human eye can see on any reasonably sized screen. Details already look crisp and clear at 1080p. The human eye can't see for all important purposes past 60 frames per second. If your game runs at 60 frames per second in 1080p, your video card has fulfilled its full purpose and goal in life. There's no need to make it any stronger. The PS4 can already reach those benchmarks, using ancient technology from 2013.
Once your game runs at 1080p and 60 frames per second, it's no longer about technical capacity. The game comes down to art design and model quality and how much effort the coders put into the game, it's purely a software issue, not a hardware issue, from here on. With Direct x 12 coming, older hardware will become even more competent, sometimes 50% stronger or more, than before. This is not a time for a new 10 times as strong gpu upgrade. There's simply nothing left to achieve. Even virtual reality goggles can look 1080p quality good at point blank range and play games at high frame rates with current gpu technology.
The only purpose of higher gpus now is for the sake of improving supercomputers, whose function isn't to play games, but to run simulations or artificial intelligence or the like. A few fringe uses for a few fringe buyers, a gpu that will never reach the mainstream.
The PS4 now costs $350. The prettiest game on computers, Witcher 3, doesn't look any better than FF XV looks on the PS4. And yet to play Witcher 3 on ultra settings, just the gpu alone for your personal computer costs more than $350. Personal Computer gaming is just a money sink with no visible improvement in gameplay graphics. Anyone who's paying for these expensive new video cards is just a sucker throwing his money down a black hole.
I assume at some point in time gpu improvements will make games look more realistic and attractive, but until they can achieve that kind of exponential jump in quality, it won't wow anyone or make anyone see a reason to upgrade from PS4 level graphics. Just being 5% better looking or whatever isn't going to interest anyone. I'll know it when I see it. If a PC game really does look infinitely better than a PS4 game, I'll be able to tell instantly. I won't need explanations about why the PC game looks better or how it has improved lighting, blah blah. I just want it to wow me on first impression and leave no room for debate.
The best games tend to be console exclusive anyway, so buying a 'gaming PC' is an oxymoron. The PC is antithetical to gaming, all the games are being made for the PS4 (or the WiiU, or the 3ds, Vita, etc), so what on Earth are you even thinking?
Companies like AMD and Nvidia should stop concentrating on inventing new, more powerful gpus and start thinking about how to lower the prices of their already quite functional graphics powers they've already invented. If they could lower the prices of their gpus to, say $50, that would help people a lot more than introducing yet another completely un-purchasable $4,000 gaming rig that no one wants or needs.
Even though it's been two years, the PS4 has no games. This is going to change soon though. FF XV is supposed to come out in 2016. Star Ocean V, FF 7 Remake, Tales of Berseria, Dragon Quest XI and other gems will soon follow. By then we'll get to see what a fully matured game designed for the PS4 looks like, instead of hasty remasters and ports. The PS4 is going to have a giant library of great games to play -- will the PC get access to any of these titles?