As I've explained before, FONV was not very good at all either as an RPG or as a post-apocalytpic story/world. Funny how some people think it's great and state supposed flaws in FO3 when it was actually FONV that had those stated flaws, not FO3.
It seems to be the difference between people wanting great writing for the world and context (FO3) while others want to simply follow written quests (FONV). The former is Bethesda's specialty while the latter is something they include simply as an excuse to get players to explore their worlds.
As long as they show that playing a variety of characters and particularly an energy-, tech-focused and ranged characters is viable (with the stress on character abilities determining outcomes rather than player "twitch" gameplay, thus keeping the RPG elements), I'll be fine with FO4. Unless they choose to reduce the RPG elements and actually market it as an action game rather than an RPG, of course, but I don't think that's likely.
At the very least, BGS is now able to ignore needing to reboot the series from its failed origins (yes, the original company went bankrupt so it failed from a business viewpoint) so they can focus on creating lore for the east coast settings without worrying much about catering to lore and events that originally took place solely on the west coast. They can move forward rather than wasting time looking backwards, and they now have enough of a customer base to not worry overtly about the fans of the originals. Assuming they maintain the RPG elements (and preferably strengthen them, not the action elements), everything should be great.
This is what I will be looking for, at least.