I think the "de facto" D&D for the forseeable future will almost certainly be the "in facto" D&D, which at the moment is 4e.
Short answer: No.
Long answer: I can't foresee any of the clones (including C&C & Pathfinder) actually overtaking the current iteration of D&D in popularity. D&D has the brand-name, has a giant company to handle distribution and development (something, bless their souls, none of those companies begin to match) and there is a significant population of the game that left 1e long ago and (barring a few rediscovereries) have no desire to go back. That's not to say these games aren't good, or have an audience, but I don't forsee OSRIC becoming "delfacto" anything except a nice SRD-like version of AD&D 1e that people will use with their old school games.
When I woke this morning I had a thought, I (and I think most people from my generation) always considered 1E AD&D the "base game" on which everything else was built (the defacto D&D) and measured. Yes, OD&D existed, but it was pretty loose, not complete enough. 1E nailed Gygax's vision, OD&D not really. 3E and 4E are too far removed to hold the defacto title. LL and S&W are likewise too loose and too unique (with strong brands). As I see it, OSRIC is going to be the in print standard by which all other versions of D&D (and clones, such as S&W, LL and C&C will be measured (the out of print will always be 1E of course). OSRIC's growth will undoubtedly be increasing in the future, but I wonder if anyone will notice. Off to work, I'll post more tonight.
It seems unlikely. But I suppose anything is possible.
In my opinion, AD&D was (and is) not the "base game" (etc.) you referred to. That would have to be OD&D, of course. Well, to be fair, IMO.
You know, when I read this my thought was that if this is true regarding 1E and OSRIC then it is equally true regarding 4E - and that really doesn't say good things for WotC who must cringe with every post that disses 4E or promotes any other version.Is 1e D&D? Yes. Is OSRIC D&D? Yes (not by brand of course). Is 1e somehow more D&D than 2e, 3e, or 4e? No. Not by any standards other than personal, individual ones.