Well, if we really are getting both next gen consoles by 2020, I think the best we can hope for is 10-12 tflop, less if one of them releases in 2019. With the push for native 4k gaming on consoles, 4k will steal away most of that extra graphics power, not leaving alot extra for pushing things like textures, lighting, depth of field, character polygon counts, level of detail distance, etc. Should mean that the devs will need to utilize the huge increase in CPU power from Jaguar to Zen in order to differentiate next gen games from current gen games. Hopefully we'll see big increases in CPU dependent things like large AI crowds and realistic physics. I want to see things like the wind-blow trees and litter from the Watch Dogs reveal that got cut from the game on release due to how how weak Jaguar is. I want those huge AI crowds like we saw in AC Unity which got cut from subsequent AC games because Jaguar couldn't handle it. I want to see more games like Horizon where characters leave tracks in snow. I want to see foliage that reacts as characters move though it. I want to see sand dunes that realistically shift over the course of a game. I want to see games with heavily destructible environments.
We do have few games putting focus on physics and mechanics related to it, like Zelda for example, with it's items and how said items can affect the world (like setting a forest on fire, grass reacting to your footsteps, grass being cut, chopping down trees, arrows on fire being put out the moment they touch water etc).
We also have Conan Exiles, which has some nice Nvidia tech, with the sand in that game reacting a lot like real sand, where you sift your feet through it, as well as seeing the sand sift around a captive you drag through the desert.
Then of course there's this: