A lot of things could be done now to show what next gen gameplay is about but it requires a lot of work and a lot of gamers can't see past regular gameplay or don't want things to evolve at all.
AI for instance. AI greatly affects gameplay far more than 1080p vs 900p. A better AI for enemies, companions, NPCs and wild life could put games on a different level than where they were last gen.
We have cameras that can detect movements and facial expressions. Implemented well it could be a game changer. No need to replace the controller with camera movements, but the cam could be used to augment features from the game. Like characters could ask you to look away or just say no (in games like ME this could get conversations to a more life like level)...
Physics, destructions and atmosphere. A game like Drive Club is a great example of immersion through weather effects. Games could make use of that on a whole new level. It could affect how things react to environment.
All we get for now are last gen gameplay with better graphics.
