The thing is, whether or not the SE becomes entrenched as "the" version to LFL or the general public--and I'd argue that it kind of already is--there's always going to be a demand for the original-original version, not from Joe Meathead who will be watching Attack of the Clones in a full-screen version, but from the film-buff/preservationist/hardcore-fan group, which will make for a more and more important demographic as the films move out of the limelight. Its the same reason why Warners put out 4 versions of Blade Runner, why Anchor Bay put out 4 versions of Dawn of the Dead, and why Universal put out 3 versions of Close Encounters--do you think these are for the mass audience? Absolutely not, those people will just watch the single-disk directors cuts, or whatever is sold as "the" edition to get. But the collectors market is huge for classic films. Thats why there is a 4 disk Gone With the Wind, a 3 disk Wizard of Oz and a 3 disk Seven Samurai. I mean movies like Wizard of Oz have a wider, family appeal too, but the collectors/classic-film-buff appreciators arguably drive it more than the forty year old moms who say "oh, look Wizard of Oz is out on DVD".
As much as optimists get blindsided by hope, I think you also have to realise that we are on the tail end of the peak of Star Wars' popularity. 1999-2005 was the pinnacle, and thats when Lucas really pushed the whole "SE only" thing, and thats also when your average viewer was buying into the SE. More people saw ANH between those years than probably the entire twenty years before it, and thats sort of created an impression upon us that is exaggerated to what the future will bring. Because Star Wars was popular at that time--it was in theaters. And on the news, and magazines, and the toys and videogames were all over Toys R Us. Kids on the playground were into Star Wars because it was "in" again. Now, it will continue to be that way, but its status as a current trend--just like Pirates of the Carribean was from 2003-2007--will fade more and more. Kids won't play with the toys as much because theres not a new movie in theaters, and so on.
Obviously though, there IS a new movie in theaters, and a TV show as well, but these will not compare to even a fraction of the mainstream popularity you saw in the days of the prequels. And over time, the classic-film movie buffs, the preservationists and the collectors will emerge as a bigger and bigger demographic, and the kids/average-viewer group will fade more and more. You'll still have the SE touted as the version of the film to judge it by, the version touted by its creator as the only valid version, but the original 1977 will gather more and more status as it gets over. You know, Wizard of Oz still has a surprising amount of younger fans for a film thats almost seventy years old, its not just viewed by fans of classic films, but those casual viewers don't really care about it THAT much and really have no bearing on its video releases, its the fans that really drive the market, that nitpick that the colors be right, that all the scenes be intact, etc.