There's been a lot of talk from some pretty big personas in the OSR about where the OSR is going (or even where it is now) especially considering the recent release of many of the early D&D / AD&D books via the DnDClassics site. You can catch some of the talk here, here, here and here.
The sky is falling. Or the ground is rising. Maybe the ground is falling and the sky is rising. Really, who the fuck knows.
Simple fact. The OSR isn't going anywhere. Putting the originals back into PDF format isn't going to gut the OSR of "old school players" anymore than DnD Next is. If anything, making the originals available in PDF format is likely to bring us the newly curious: "Wait, you mean there is a version of B/E that I can download for free and the rules are clearer than the originals? Score!"
This isn't us losing from a limited pool of "old school gamers" but having the opportunity to expand that pool with the release of the classic PDFs. The question shouldn't be "how do we not lose players to the re-released classic rules?" but it should be "how do we embrace the players that are just now finding Old School Gaming (or returning to Old School Gaming) thanks to the classic PDF reprints?"
It's the time to remind the gamers out there that Labyrinth Lord is a clearer rewrite of the BX/EX rules, Swords & Wizardry is the OBS with some of the original supplements. OSRIC is AD&D 1e much like how it was played. Why stress these three? All are free and they cover much of the Old School Experience.
Then, once they are here, once the assimilation process starts, you hit them with LotFP Weird Fantasy, BFRPG, Microlite 74, ACKS, ASSH, C&T and all the rest.
I mean, folks do remember you can play more than one game, right? It isn't "one and done". You aren't stuck on the first game your find.
Will the OSR "change"? New blood always bring changes. Still, the OSR at it's very root is "Old School Gaming", and that will never change.