Not sure if this is late news or not, but this was filed yesterday by The Verge. Pendelton Ward quietly stepped down as the showrunner of Adventure Time somewhere in season 5, BUT he will be on the writing/storyboarding crew still. I'm not sure if this is exactly "big news" or not, but yeah, it happened.
The creator of Adventure Time, simultaneously the most colorful (aesthetically) and the darkest (mythology) cartoons out there right now, has downgraded his role. According to a Rolling Stone profile, Pendleton Ward quit as showrunner at some point during season five. The relevant piece from Rolling Stone:
He says this not with sadness or frustration, but with relief. "For me, having quality of life outweighed the need to control this project and make it great all the time." So he stepped down from running Adventure Time to become simply one of the show's writers and storyboard artists.
Asked if he'd ever want to create another TV show, Ward responds with horror: "No, never. That sounds like a nightmare!"
Ward has remained (and presumably will remain) on the show as a writer and storyboard artist. And according to the profile, he might consider writing an Adventure Time movie. Feel free to think of Ward as tucked away in the front pocket of Adventure Time's future.