Grah. I hate the idea of this crap. Apart from some VERY experienced shooters, using two weapons at once is stupid. Certain situations, like defending multiple entry points, or laying down a decent amount of firepower without a decent weapon. Shooting two weapons puts alot of "stupid" fire down the range. I, for one, would like to put two shots into a guy accurately, and move on, instead of this flashy crap. Why waste eight rounds when I only need two? I don't like the whole idea of dual wielding. I suppose for certain characters, that makes sense, but why implement a "tacticool" feature in a game where ammo is supposed to be important? Let's be real here. There is no real arguement here.
I can't really argue with that rationale. If you are playing hardcoe, you want every bullet you fire to land and even if you have bullets to spare and want to let them fly, using an SMG that fires the same ammo type would be more accurate and have a better rate of fire that dual wielding 2 pistols. Still, I'd have to say that dual wielding is more "true to real life" than the bullet-time like VATS feature. As long as the appropriate advantages and penalties apply to dual wielding are applied, I don't see why it shouldn't be in the game as long as you can freely toggle between single handed and dual wielding styles.
Personally speaking however, I'd much rather see selective fire on automatic type weapons than DW, a feature that was in FO1 and 2 but sadly excluded from FO3. With certain automatic weapons you can switch from single fire (most accurate) to a three round burst (less accurate but better rate of fire), to full automatic (least accurate but best rate of fire). It would make perfect sense in hardcoe mode, since ammo has weight, you can forego the extra hunting rifle (for long range) and sidearm, unless of course they can somehow fire the same ammo type and just use full auto for mid range, the 3 round burst for long range and single fire with an attached scope for sniping or dispatching small but aggressive wildlife.