I'd give you Vampire at it's height as one that might have had some traction in some circles of the populace... and yeah, to another part of the populace they'll throw out any nerdish buzzword they can think of that might even come close to fulfilling the question "Do you know what a roleplaying game is?" I'm sure we'd get occasional responses like "World of Warcraft?", "Warhammer?", "Lord of the Rings?"
But other than those rare outliers, we're going to see 'D&D' still be the go-to answer for any questions about the tabletop roleplaying industry. And there's nothing wrong with that... but it just shows how much of an uphill battle it is for any company to reach beyond the niche to find new players to pull in.
In as much as competition between WotC and Paizo is a good thing for gamers (and I firmly believe that it is), we should be hoping that the competition for market share drags on for as long as possible. It's impossible to say which company will "win" in the long run, if either of them does. For as long as there is competition we can expect the two companies to influence each other when it comes to game design as they go through the inevitable game system cycles of rules bloat and paring (usually in the form of new editions or other reboots). If 5th Edition does something particularly well, you can bet that Paizo will be consider adopting that thing (or some variant of it) when they eventually get around to 2nd Edition Pathfinder.
It is not insignificant that the head publisher at Paizo is reading this thread!
Again, this is very good for consumers/gamers. It spurs both companies on to do their best and speeds up the evolution of gaming as a whole. I tend to view this evolution as cyclic more than linear, but that as the circle comes around and around the stylus engraving it etches deeper, if that makes any sense -- RPGs now seem more "advanced" to me than they did many years ago.
Paizo and WotC have already been compared to death, but I'll add that the struggle between them continues to feel like the classic "giant vs elf" battle, with WotC having more raw power by virtue of money, tradition, and name recognition but Paizo having the advantage of agility, maneuverability, and... intelligence, but I don't mean that in the way that it probably sounds (for a variety of reasons I think Paizo is capable of making good decisions more often than WotC is).
In general (forum atmosphere aside), I think it's easier to *like* Paizo -- it's more in tune with and able to be responsive to the gaming community, for one. And I'll happily switch over to whatever new edition of Pathfinder Paizo eventually comes out with when it's ready to pare down the bloat and deal with some other issues that can make the game difficult to run. And I fully expect 5th Edition to have developed its own problems by then.
For better or worse, we can expect a much faster rate of game system evolution while this rivalry stands than we got back in the day when TSR really was the only show in town that mattered. I like to think it's a good thing.