Just to be clear here: do you mean the kind of 'branching campaign' the original game had, as opposed to, say, the sort you find in 'hardcore' flight-sim titles like Il-2? I realize it sounds like I'm being more pedantic than usual here, but it's a fairly big distinction; the difference between playing a limited number of scripted missions where you can determine which path you take, and a free-form, almost strategy-game viewpoint where you perform missions on a workaday basis to move the frontline around; the big shot here being of course that with the sheer variety of possible outcomes, it's difficult if not impossible to actually have a running narrative in the sense the original game had - the narrative is one created by the player in his own mind, hard to write for; not the sort of thing you expect from a big-budget, glossy Wing Commander game (which probably helps explain why it's never gained much popularity outside of the niche flight-sim community.)
Personally, I favor a very limited sort of dynamic campaign; one with a good number of scripted missions to give it continuity, and yet stretches of 'generic' gameplay where you can just take off and smash through whatever (or get smashed by whatever), and reap the consequences more fully in the scripted missions. I'm actually thinking of Emperor: Battle for Dune as a model here, though even with its budget and a conscious effort made to divide the map into provinces and distinguish them from one another, it did have too-long stretches of 'sameness'.
