Interesting how this comes right on top of some comments on the Marvel Reading Order project:

Marvel have long been hinting that AvX is going to definitively solve one of the 'problems' that affects the X-Men: in a world where anybody can be a superhero, why would the general population have it out for mutants?...

A separate, parallel world for the X-Men to run about in would definitely help Marvel in two ways: it would shake the X-Men off their shiny movie-driven Avengers franchise, and it would give the X-Men a place to be hated and feared in. Is that what we're seeing here?

This is all pure speculation at this point, of course, so i won't start ranting about the end again. But there was some wild theorizing earlier that the coming of the Phoenix in AvX would end in a DC-like reboot of Marvel, and this sounds like a half-step in that direction. But one that would be easy enough to reverse, i suppose. Anyway, i'm officially Not Reacting to this yet.