Austen exits X-Men, Marvel: Newsarama has official word from Chuck Austen that he's leaving X-Men -- and Marvel -- with Issue 164:

"Obviously, no matter what the facts are, a lot of people are going to form their own opinions. Speculation is the lifeblood of the industry, in more ways than one [laughs]. And there will be room for speculation, since I don't want to get into any real details. Those specifics are between me and Marvel, really.

"But the simple answer is: I chose to leave, and it was a tough decision. I didn't 'finally realize' anything, I was clear on the situation from very early on, and had discussed it privately many times. I just don't talk about my employment situation publicly, so very few people knew. ...

"... I left because, as I and Joe Q. and others have said in recent interviews, Marvel has changed its internal policies about what is, and is not acceptable in their comics, and I was finding it very difficult to write that way."