Next gen gaming wont be that demanding. A PS4 is pretty much a slow 8 core cpu and an HD 7870. 2 of its 8 gb of ram will be reserved for os and apps etc.
I am assuming your referring to next gen consoles, since PC's don't really have generations.
With that said the baseline spec is pretty clear. As with this gen expect pc games to be held back by the spec of consoles.
As for pc only games, i'd expect the nvidia 7xx range to be the go to higher end card over the coming year.
Honestly, a decent cooler and overclock on that 920 is plenty still. There isn't a single GPU graphics card out there that can saturate a PCI-E 2.0 yet, so you are fine there too. Buy your better GPU and enjoy. Unless something dies, you are fine till at least Broadwell.
My only problem is I am not a skilled overclocker. Mostly I just use the built in OC system, but I don't trust it. I know enough to know it sets my voltages way too high and the chip runs real hot. The auto OC puts it around 3.5 but prime 95 will get it up to 80C pretty quickly which is where I generally shut down Prime 95.