I think the matter of the https://www.youtube.com/watch?v=9K1Kd9mZL8g applies here.
You can see almost instantly, with the https://dl.dropboxusercontent.com/u/87106516/Fallout4_E3_Salesman.png, or https://i.imgur.com/uGkazlf.jpg that we are not quite at photo-realistic.
Clearly this is a design choice, hands are a little large, facial features are a touch too expressive for photo-realism.
The advantage of this is that the discomforting impact of some raider's head being blown off in Fallout 4 is less
than a character in Metal Gear Solid having their internal organs messed around with.
For emotional story beats, the character expressiveness supports that, not hinders it
rather than an attempt at a more photo-realistic, less emotionally expressive face (Aiden Pearce anyone?)
Next, most games with more photo-realistic representations don't have tons of objects that can be dropped/positioned in the world.
What we're left with is an inconsistency, if a deliberate one.
The world looks gorgeous, trees, water and so on.
Characters have more realising weapons and clothing, yet have a slightly stylised appearance.
And Dogmeat doesn't hold up, though good, against some photo-realistic dogs in games/movies (though they may not have to fight or fetch stuff).
Finally, we are still fed games trailers that are either CGI movies or enhanced vertical slices,
so there's a slightly lower fidelity due to being honest - this is what the game is actually like.
Are the graphics good? Sure.
There is some logic behind the 'concerns' but after playing the prologue, we'll soon be immersed.
Fallout 3 had emotional 'world vista' moments, Fallout 4 certainly will.