This article by Robert Tracinski covers the "four cornerstones of the mainstream or ‘orthodox’ school of Objectivism that formed in the 1980s after Ayn Rand’s death. These propositions, having to do with the nature of Objectivism as a philosophy and how it should be organized as a movement, were solidified between 1985 and 1989 and articulated by Leonard Peikoff and by Peter Schwartz, with Peikoff’s approval and support. All of them are now coming crashing down in one way or another." The 1980s Called, and They Want Their Objectivism Back | The Tracinski Letter
While I think he is a bit harsh on the Brandens, Barbara in particular, I agree with his overall take on the continuing schisms and purges that plague the Objectivist world.