Ultimately the new films won't take the franchise forward because they have gone back to the beginning. We will probably have a third film and that will be that because the TNG films are still to fresh in peoples memories to have a re-boot.
So what your saying is after 3 "reboot" films they will stop because people will still be thinking about the TNG films?
I think after this new film most people (non-trekkies) will have forgotten of the old Star Trek in my view.
The first Abrams did OK for itself in the box office, but I think a lot of people were put off it as they just thought it was another Star Trek film but this time made by "the Lost guy" so didn't go to see it in the cinema. But with word of mouth I think these people may give the new one a go as they've now heard it's nothing like the old films. More people going to see it = more money for the studio = more ST films being made.