There is something that I don't understand. I DM a group that plays 4e and another one that plays Dragon Age. When our Dragon Age campaign comes to an end, I will tell my players that I know how to play Castles and Crusades and 4e, so if I am going to be a DM again, they have to choose one of these two games. I will be more than happy to play any other game (Pathfinder, 3.5 e etc) as a player if they want to be DMs. Actually I prefer being a player, last time that I played as such, was 18 years ago (a lifetime!) when I was playing AD&D.
Because there are two things that make me love the tabletop RPG games. The epic story that evolves session after session and my friends around the table. The only thing that changes is a small detail. The rules.
There is no schism if you love stories and your friends. The worst thing that is going to happen is that your wizard will have different spells. So what? I enjoyed the first trilogy of Salvatore about Drizzt, I enjoyed the LOTR and I am currently reading The sword of Shannara by Brooks. All different books, magic is different, the world is different but what remains in your mind after finishing each book, is the story. Even Elric of Melnibone, which I didn't like all that much, gave me an experience and I am never going to say that I regret reading it.
So, in my opinion, the only thing that creates schisms and could prove fatal for the game is our ability to adapt. After all, it's just that... Rules! Nothing that can't change!
(Sorry for my english)