I already fucking said, before the the PS4 or X1 even came out, that the improvements will be lighting/shadow and physics, good lighting and shadows take a shit ton of RAM and that's where the larger memory pool comes in, and physic will open up for new game play possibilities which would be good too. The problem though, is that neither the PS4 and X1 will have enough power to really open up a can of whoop ass on the physics department so we will not see actual impressive physics in the games, but it should be enough to "wow" the 7th gen console only gamers enough while the PC gamers keep crying about how console gaming drags down advancements in video game graphics and interaction.
Also, X already looks better than RDR at this stage if you have a pair of working eyes and it looks better than the alpha videos from the past trailers, it will probably improve again when we next see it as well, I'm not too worried about it since I was mostly paying attention to how the combat worked rather than concentrating on the graphics along. "HUGE SUCCEEDED!" like wtf is that lol......
Can't compare Bayo 2 with GoW 3, one has free roaming camera at a faster pace and the other one is a static camera and much slower game play, I've demoed Bayo 2 and I've finished GoW 3, both are great looking games, Bayo 2 looks really good in person and the video compressions fuck it up because the action is so much faster than GoW 3 that GoW 3 feels like a game for turtles is what's going on there. You can't even figure out the texture details in Bayo 2 videos and things look blurry, but they are super clear when in person.