The only reason people have used map nodes is because past engines were not capable of making giant maps, maybe this engine can (Beisdes Bethesda who's to say?).
How is the random encounter system better? I mean back where everything was turn based and people could only do a certain amount of damage against you before it was your turn, sure it was better but would you really like it if you decided to go get a snack while you were waiting for the map to load and you got slaughtered by a radroach or something while you were gone? I wouldn't. (When I played New Vegas I left it running (not paused) to grab snacks, etc. and never died.
I seriously doubt that any sandbox map would allow for weeks of travel time between settlements while still having a reasonable timescale. And I don't understand, why would you not pause the game when getting a snack? If you do not pause the game while you are not there, then it is hardly a flaw in the game's design or anything. That's just for the sake of convenience that can be remedied by pressing the pause button anyway.
I think we all know it will be the Creation Engine, and I'm fine with that. I hope it is heavily modified (more than it was for Fallout 3 and New Vegas) to accommodate the needs of Fallout, which I think includes a map node system.
What's so bad about a node system if the maps you travel between have areas to explore around them, but the worldspace would just be smaller than the main world of Fallout 3 or New Vegas? You can have Bethesda-style open worlds without feeling like you're completely tied to one region, and you can have a lot of varied environments.