The leap you can see between late PS2/XBOX titles and early PS3/XBOX360 titles was pretty much related to resolution: from what I saw, the best looking PS2 games, emulated on PC and rendered at higher resolution, look a lot like the early titles of 7th gen. I mean, God of War 2 looks incredible. The same for the GameCube.
The leap between last-gen late titles and this-gen titles is mainly related to shaders and post process, as you can see in inFamous. There's a leap there, and from a technical standpoint the leap is as big as ever (maybe bigger, if you consider raw numbers), but the human eye probably appreciates more a leap in resolution than in effects.
Also, late PS3 titles, extremely optimized for the machine, showed extreme shaders and post process (like Beyond: Two Souls) that can maybe give a "next-gen feel", but the rendering in these titles is extremely controlled, and the memory holds only a minuscule part of the game world at any time: it would be impossible to realize a fast paced open world game that looks like B:TS on PS3.
Of course, what really matters and what always matters is the art style, and that's why MK8 looks so amazing: I am sure that when MK8 comes out someone will stop his/her kart on the worst-looking track, in the worst looking-area, take a 720p screenshot, post on GAF and assert that MK8 looks like shit.
What is disappointing to me is not related to the graphics, that for what I was are already awesome on 8th gen, but gameplay: up to this point I didn't see any real next-gen experience, something really new that can push console gaming forward. Maybe Deep Down will do the trick, I don't know, but current games are basically the same old games with better graphics. The only console that, up to this point, has actually used the included new technology to some interesting extent is the WiiU: if consoles cannot capitalize on new ideas, one year from now a PC sized like a XboxOne for similar price will be more compelling even for the console gamer.