Fallout 4 will be amazing in its own right and people will still find 'caveats' for themselves to be upset with it because it didn't turn out to be how THEY envisioned it. You can't please every single fan, no matter how hard you try.
Yet, knowing this, people will insist that the game is bad because X reasons... how they should phrase it is that the game just isn't for them and be done instead of frothing like the damn thing gave them rabies.
I grew up on Fallout 1 and 2, and I've played 3 and NV. I liked them each for what they managed to bring to the table, took what I disliked about them, and ignored those bits or found mods to murder said bits to dust.
For me, I'm updating my rig specifically to be able to play Fallout 4 with no issues at all, and I know I'm going to love it, because the E3 gameplay alone gave me a boner. The graphics were wonderful, it had that recent Fallout feel, I'm not sure what the fuck everyone else's problem is about. I liked the voice acting. I liked how they're handling character customization. The intro to the storyline seemed a little confusing (I didn't look into it) but that's easily able to be set aside.
If something doesn't fit, I can add my own headcanon to it until it makes sense. That's the point of a game, something to be played for pleasure with your imagination. If you can't use it and want everything spoonfed to you, go watch a fucking movie. I liked the weapon crafting/customization. I like how you can make your own little 'settlements' and how every previously useless item now has a point for being broken down into specific materials for said building and crafting system.
It's like they had a bug on my phone and in my clothes and were listening in on my conversations with family and friends about how I'd like to see things like these in a new release, and I'd even said, "Wouldn't it be badass if they set Fallout 4 in the Commonwealth?" and bam, the confirmed announcements about it literally made me go "WHAT?! AWESOME."