I'm of two minds when it comes to the "talking" head stuff, and whether it has a place in modern games.
On the one hand - I can't help but think it's rather superfluous at this point. There's a pretty obvious reason for why Fallout 1 and 2 used them. You can get sufficient fidelity from just the base game models in a game like Fallout 3 to serve all of the same purposes the talking heads had in Fallout 1 and 2. I'd also say there's an argument to be made for not jolting the player around with superfluous shifts, and keeping the graphics all on an even keel. (That used to be a big deal back in the day, when they started using the game engine to produce the cinematics, for that very reason. I-76, for example - purposefully kept the cinematic in-line with the in-game graphics, even though they were hardly remarkable for the time.) There's certainly something to be said for keeping the graphics and interfaces consistent throughout, I think.
On the other hand - what we have in Fallout 3 basically
is a talking head interface. With static backgrounds and limited animations. I would say that in a third/first-person game, that bringing up the iconic dialogue interface with the techy doodads and such would be superfluous (maybe not in a hypothetical FO1/2 remake, but in general...) I think that would be too jolting and superfluous a transition - akin to the game telling you NOW YOU'RE GOING TO TALK TO THIS GUY!
) You'd still have to find a way to transition between the models, however, without it looking obvious. I can't think of anything particularly elegant, and I'd have to see it in action before being able to really judge different ways of approaching that.
As far as graphical fidelity, and how it might be improved with this sort of interface - with Fallout 3; it's still largely subjective, but I'd say that the Fallout 3 heads and Fallout 1/2's talking heads are about on par, at best. The heads in the old games were nice, and they have a lot of character - but they have that mush-mouthed, lippy thing going on that really dates them, I think. Since this topic is about remaking Fallout 1 and 2 - I'd think you'd sort of need to do talking heads, just because the old ones had them. But I'd imagine that by the time Fallout 4 rolls around, we'll have a significant enough graphics increase to really make the talking head thing even more superfluous. I think it works fine in a pulled back camera where you don't really see the characters faces otherwise. But in a first/third-person game I don't really see the point. ("Hi, I'm an NPC. This is what I look like. You can get right up close to me and see what I look like and examine me from all angles. Oh wait, you want to talk to me? Hang on a sec... THERE, THIS IS WHAT I REALLY LOOK LIKE! Count my pores! I said
count them!!"
)