From a gameplay perspective what do you think will be....

Most improved This gen? I think that open world games like Fallout will benefit the most. Less pop in, better textures, bigger environments, should run smoother. Im excited to see what devs can do with cities. There should be a lot of variety in enemy a.i as far as looks. Buildings and houses should all be accessible. No more cities with 100 houses and 98 locked doors.

More destructable environments.

Probably interactivity with the environment. Half the reason I always disliked console games that weren't super closed off was because they cut so many corners to get that open world. Nothing was destructable, the door thing, everything that you could interact with had a special animation and feels forced as a result, hidden barriers were everywhere, the games took a huge graphical hit (compared to the system they were on), and the gameplay was usually very shallow. I'm hoping that we can get more 'in the wild' type of thing where the game is almost completely organic and the game can literally be a sandbox that reacts to you, even more linear games.

Interactivity with environments is a PS4 exclusive feature because only the PS4 has enough power to have next-gen features.

Xbone games will be mostly linear and static with 2-3 enemies on screen at once.

the last generation was about moving from the established mechanics towards the 'feel' of the game. We got improved digital acting which increased the fidelity of drama, to open world games which had embedded narratives that heightened the atmosphere and intensity of exploration(fallout, skyrim, demon's/dark souls). Next gen will be about taking that further with bigger worlds and more things to do while making sure those things are meaningful.

I think the benefits of more hardware power benefits from the details in the world, like more objects in the scene, better particles like wind and dust, more people on screen, etc.