WotC needs to harness the exact power that's killing them: individual creativity.
D&D has always been about that, with homebrew worlds, campaigns, adventures, monsters, etc. It's just, people didn't really have a way to publish to the masses.
With the OGL and so many different creations out there that take advantage of it and the ease of internet publishing, now WotC isn't just competing with Paizo or whatever, but all of the amazing creative minds out there. Just take a look at all of the amazing, talented work coming out right now. Why would I buy the next generic WotC adventure when I can buy Hammers of the Gods?
So, what can WotC do? They can "publish" it all.
Create D&D Next as a hub for all that content. Create a barebones, lean and clean system that can be hacked to pieces and then provide a sort of "App Store" for D&D Mods / Hacks / Adventures / Settings / etc. And, use an App Store-like system for ratings, reviews, featured content, etc.
There are some hurdles of course. They'll need guidelines on PDF design and logos and all that. But, people were fine using the OGL - why not this system? And, instead of leaving the OGL out there for someone to make money off of the game without WotC getting a cut, WotC can actually profit by taking a small fee for each transaction in exchange for the server space and distribution (like Apple does with the app store).
People are creating it anyways, so why not give them the tools to get it to the largest audience? Imagine if the next Into the Odd or Tales of the Grotesque and Dungeonesque or Lamentations of the Flame Princess or Adventurer Conqueror King were simply modules for D&D Next? Now, those creators might not actually go that route, but there are certainly people out there that might take advantage.