In regards to Paizo maybe getting to buy out the D&D brand, maybe they'll get their chance if 4th edition debuts. I think a new edition of the game will be the straw that breaks the camel's back.
Honestly, unless WotC comes up with something really revolutionary, what more can be done to improve the game? I'm not talking about updating errata and tweaking things, I'm talking about the whole shebang.
One reason I will never buy a 4th edition product is that I can't afford to spend the hundreds of bucks just to update my game.
The other reason is that I have enough existing material to keep me happily gaming the rest of my life.