I've made an assertion on prior occasions that one of the key factors which I feel will determine whether Dungeons & Dragons 5th Edition can make a comeback is if it's presented as OGL (open game license)....specifically, goes back to the 2000-2003 style OGL and SRD setup that 3rd edition spawned, and not the GSL of 4E. When you look at rpgnow.com and other online ebook retailers you can still see the fruit of the OGL, rife and pervasive. Not a day doesn't go by that we don't see a new Pathfinder tome, some D20 variant, or OSR module or retroclone being released. Some might argue that this is evidence that the OGL did lasting and permanent harm to the D&D brand by allowing it to fragment (in such a model 4E would just be the nails in the coffin) but I would argue that moving away from the OGL was what really let it out into the wild.
In 2004-2005 we saw the D20 bubble bust, when the glut of D20 based products reached critical mass and store owners couldn't dump their product fast enough. A handful of the most creative and resourceful third party publishers managed to swim when everyone else started sinking, and we know who most of the survivors are today (Green Ronin, Monte Cook, Paizo, Crafty Games and a couple others). The market didn't evaporate wth the arrival of 4E in 2008, however...all it did was spawn new paths or directions by which new 3PP could arrive on the scene, and the GSL was an effective deterrent against keeping with the brand-name D&D; in pharmaceutical terms we suddenly had a spawning of generics in the market: Pathfinder and the OSR movement being the top dogs in this creative venture.
Most people in RPG publishing are in agreement that had 4E stuck with the OGL then it is likely there would have been more buy-in and support from the 3PP. Odds are we'd have at least seen a better effort at adopting (and fixing/appending/expanding the options for) 4E D&D if that had been the case, which would have fed into a possible synergy for the game between it and its potentially expansive 3PP options, allowing the fan base to look to more choices than it actually got in reality.
Of course what did happen instead is someone else (Paizo and the OSR crowd) grabbed the OGL by the horns and kept it alive, with new brands. Pathfinder and its process is obvious, but if you look at the OSR as it's own umbrella brand, under which rests a bunch of little connected and mostly compatible efforts, all also OGL, it's fairly obvious to see where all the creative effort in publishing went...and remained.
So it's with some curiosity that I realize that in 2013, D&D and Wizards of the Coast spent a great deal of time courting the player base that was interested in play testing, but as far as I can tell it did nothing to try and court the interest of the other side of this equation: the 3PP support. Sure, it's easy enough to say that Hasbro's lawyers have WotC on a short leash about this, and I imagine someone at Hasbro must imagine that the OGL had long term damage on their brand and sales (after all, someone buying a 3PP product is not buying a WotC product), but surely they must realize that the problem lies not in ignoring the OGL, but accepting the realities of the Pandora's Box they opened nearly fourteen years ago, right? That the way to grab the audience for D&D and bring them back into the fold is to embrace both the consumers and the creators of content....that the 3PP sales are not something people buy in lieu of official content, but something they get in addition to it. The health of the game will be determined by the ability of its fans to partake in the process, and a structured OGL environment is far and away the most effective legal process I've seen in this hobby by which one can creatively partake of it (and occasionally make money doing so).
I have a mostly complete revision of my Realms of Chirak book sitting around waiting for me to decide what to do with it. I have a Pathfinder-statted version which I use for my own game tables since I formally embraced Pathfinder, and I have a more generic version which might like to nestle in with D&D 5th Edition, if only I knew whether or not it was worth the effort. A year or more before 3rd edition D&D ever arrived on scene WotC was courting interested 3PP with the prospect of having ready-to-go content right out the gate for the new edition, and it was a gamble which paid off in spades. I doubt they will even dare to attempt such this time around, but I can safely say that a failure to embrace the creative content-producers of the hobby is going to backfire on them. In a world where you have Pathfinder and it's full OGL toe to toe against the fresh and somewhat uncertain D&D 5E, supported by an immense volume of old product online but otherwise locked in.....if WotC doesn't see that they're about to find out if the gaming world can handle the equivalent of a PC vs. Mac split......(and yest the Indies are the Linux OS in this analogy)...well, then I just don't know what to say except: Please make it possible to support your game through the release of my own products. I want to be on board with the next D&D, but you guys need to own up to your greatest triumph: the OGL. Without it, I don't see how you can do more than flounder at the edge of the hobby.