The Walking Dead has been picked up for a fourth season, not a shocker. What is the shocker (or not depending on how you look at AMC's track record) is that Showrunner Glenn Mazzara will step down after season three. Rumors have swirled for a while that Mazzara was unhappy running the show, and now it looks like it has finally come to a head. However, AMC and Mazzara both say that the split is amicable, with them issuing this joint statement, “Both parties acknowledge that there is a difference of opinion about where the show should go moving forward, and conclude that it is best to part ways. This decision is amicable and Glen will remain on for post-production on season 3B as showrunner and executive producer. AMC is grateful for his hard work. We are both proud of our shared success." Mazzara and Executive producer and creator Robert Kikman, as well as Executive Producer Gale Anne Hurd all issued solo statements as well.