Hmmm...
I'm pretty picky about what I let into my game, and since I don't have a large budget or enough time to go through the d20 stuff, I generally limit my players' options to the WotC books. The only exception is stuff by Monte, which I basically view as official. He's also provided a nice counterpart to the sages more unusual rulings.
I suppose that if WotC were to suddenly become what TSR was in its final days, I think Sean/Monte/other core desigeners could easily use something like Malhavoc to keep the game going. Maybe even launch an unofficial 4e. With the OGL out, our hobby really isn't tied to the fortunes of one company anymore. I'd like to have a strong WotC leading D&D, I can't say how much I appreciate them for having the gumption (that's right, gumption) to make 3e (and make it good), but if push comes to shove, I'll choose the desigeners that built D&D over the company that publishes it.