The Witcher 3 set the bar.
CDProjectRed is a smaller team, with a smaller budget, and they had less time to make The Witcher 3. There is no excuse for this game not to AT LEAST look as good as that one.
I also have no doubt there will be at least a few open world RPG's shown (Guerilla Games Horizon) in the next couple of days that will look better than Fallout 4. No doubt in my mind.
Just goes back to my previous statement....and if it looks better so what?
It won't win game of the year because it has better AA.
Fallout 4 will IMHO have the superior gameplay and that is what really matters.