To some degree graphics reached "good enough" for me with Crysis like 5 years ago. Recently though it's being hammered into my skull. I've played three games recently, Far Cry 3, Max Payne 3 and Hitman: Absolution, which look AMAZING. Like, as lifelike as I think games ever need to look. Any more lifelike might actually look worse in a weird way.
So did you check the Crysis 3 trailers and tech demos yet, how do you feel they measure up to the games you mentioned? The plants certainly look very good in Crysis 3, but I am unsure how much they will matter when you play.
I'm now replaying Far Cry, and while the graphics look old and fake by today's standards, I still like how lush they look, and I'm still impressed by many of the scenes. I feel the graphics are quite adequate for the game. But I still recognize later games like Crysis 1-2 and Far Cry 3 look even better.
It is hard to say if this is now as good as it needs to get. It depends how much more eye candy are they able to provide with what kind of horse power. I usually switch off e.g. edge antialiasing (16x MSAA or whatever) by default, as to me it seems to provide quite minor visual enhancements compared to the hit on performance, at least when playing on high resolutions like 1920x1080.
As some other discussion on this suggested, not all games need to try to be ultra-realistic looking, but stylistic, like XIII or Borderlands. Maybe many games are missing the point when they try to look realistic instead of stylistic. A bit like if cartoons always tried to look as realistic as possible.