As with previous generations, I expect to see some minor graphical increases from the launch titles but it will be a year before we have that game that makes us all go WOW! Which ever console that may be?
Perfect example: Gears of War, this gen.
Purveyor of pixelated pornography since 1984 http://cdn.list25.com/wp-content/uploads/2011/11/aboss.gif
we'll get a few games that make us go WOW at or near launch. Look at Oblivion which came out a few weeks after 360 launch compared to the best Xbox had to offer, it's a landslide of difference.
Although I dont' expect the difference to be that huge, graphics can only get so good until you can't improve them. I would bet this gen or next gen we'll reach a point where graphics can't get any better, the only thing you can do is improve the other things like Ai etc.
It'll be interesting to say the least that's if I continue to game, which doesn't look like it'll happen, no BC, no used games, always online.... yeah no thanks brah