Among larger society, roleplaying of any fashion is "Lame". To the extent that the SCA "I use foam weapons to beat my friends up, drink beer and yell about wenches" guy is lumped in with D&D players to the general public.
That opinion is similar to other geeks. The public gawks and laughs at the lines of costumed nerds camped outside of the theatres to see Star Wars. Trekkies get it too. And dare I say, the opinion of WoW and other things, to people who know what they are, isn't fabulous; look at the South Park episode dedicated to WoW.
4e will not change the average member of society's opinion, because it's still "Nerd stuff". It involves math, reading books, and playing pretend, which is just odd to the average person as a pass-time.
Inside the Geek umbrella (and under the gamer umbrella), all sides sneer at other sides. When I say "Furry", do you not roll your eyes and sigh? When I say the words "LARP", do you not snicker? Do you not think of pasty frufru goths dressing up and passing notes in a playground at night? There's feuds and stereotypes between geeks, and between gamers.
Among the gamers that I know, D&D is the "lowest common denominator" of tabletops. The Gateway Game, if you will. Everyone who's ever thrown dice knows what a +1 sword is. It's the most widely known, widely played game, and it's the easiest game to find players for. Some gamers sneer at the fact it's Level based, some sneer at its Hack'n'slash focus, others hate how limited it is, and so on.
4e isn't going to change the opinions of those who think "D&D is, and will always be, the lowest common denominator".
4e will possibly do what 3e did: bring into the fold the people who had stopped gaming 2e, and had drifted off. It might alienate some of those people. But it also might attract more young crowds, with shiny, cool stuff.