Bendis sort of addresses the X-Men rumour in a post on his message board, pretty much dismisses it and boasts that what he is working on after AVX is so much more than that. I suspect they're waiting for the next big con to reveal just exactly what he is working on. Axel Alonso also stated a few weeks back, or maybe it was Breevort, that they already have the next Avengers writer in place. I'm guessing we'll find out both these things in the summer time.
Also what's funny is that Rich of course is going with his previous story. The sheer arrogance of this guy, fascinates me.