If you've watched the Uncharted 4 demo at E3 2015, you'll have seen fully destructable environments and then a minute in Drake and Sully will jump in a Jeep that is fully controllable by the player for a several minute long chase sequence(which wasn't even the extended demo.) The amount of area covered in that one scene looks to be around half the size of GTA4. Who would want to see a open world game with the Uncharted covering mechanic further refined, the melee combat in Uncharted 3, and the weapon combat in The Last of Us. I know I would. Or how about an open world The Last of Us? I wouldn't mind seeing what they could make either with your standard open world game or a post apocalyptic game like The Last of Us.
Here's the video if you haven't seen it.
https://www.youtube.com/watch?v=zL46dpNEPPA