I'm sitting here literally laughing at the people who are arguing with the OP.
The best console developers code to the metal and pull off amazing feats precisely because they are targeting a closed box system. You can't do that for an open platform like the PC.
This is why games like Halo 4, Uncharted 3, Killzone 3 and GoW 3 look so mindblowingly good, far better than anything you will see on a PC even using cutting edge $2000+ hardware from 2007.
This isnt even factoring in the likelihood that the PS4/720 will have some hardware features by default not found in normal PCs such as a ton of cache, either a ton of ram 16-32gb or a very high memory bandwidth, or an SSD by default that the developers could code specifically towards to pull off feats not possible in PC Games. For example, devs will never release a PC game that can ONLY run off an SSD, but they can certainly make such a game for a next gen console that only supports SSDs and not traditional slow HDDs.
Honestly the point the OP is illustrating (that a closed box can pull off amazing things simply not possible on an open platform because devs can code down to the metal for a closed box) is so self evident and obvious that I didn't think it even needed a thread pointing it out.
I am baffled that people are arguing with the OP.