I think I am going to try and "rerail" this thread.
There is no doubt that WOTC has a superior market position in the RPG market. D&D is the game that started them all and the one most likely to be found in Barnes & Nobles or Borders. But when you get down to it, I think the more important place to find games is in places where people actually will play them, be it the high school lunch rooms, college commons, family room, or at your FLGS. Those people are your sales and marketing force.
Even though 4e has had tremendous sales up to this point, the GSL has harmed the industry. Instead of everyone building off the 4th edition, everyone must either convert to the GSL, stay with the open system or come up with their own proprietary system. If it is true that 4e has split the community, WOTC has totally screwed up IMHO. Before they had most people playing 3.5e, with some people branching out to try other systems. Now it anyone's guess with the numbers, because they shrunk their own market. Instead of all these 3pp under their roof, they are out there working on their own systems.
My point simplifies things assuming that if someone buys one they wont buy the other, which I actually don't agree with. Liking 4e does not preclude anyone from buying Pathfinder, nor the does the reverse. But it does mean that there may be two major systems that people have to buy for, and because of the GSL, 3pp are restricted in supporting both. 3pp like Necromancer have to choose which to support and because of the draconian nature of the GSL I'm not surprised that they are staying with 3.5e and its derivatives. It just means one may have to buy two systems to play with all of the available product out there.
My whole point... It's market share that will determine the outcome of this GSL fiasco and you have WOTC and its lawyers on one side and Open Gaming on the other. Historically speaking T$R did do itself any favors by restricting its game and IP; in fact it was WOTC's opening up of 3e to everyone that saved D&D and made it the powerhouse it was. So long as the GSL is not Open Gaming, 3pp will not put any major support behind 4e. Heres to hoping that everyone has room for both.