Today, Bungie announced that its chief operating officer, Pete Parsons, has stepped into the CEO role, as studio president Harold Ryan steps down. The reason behind Ryan's decision was not released.
The news was revealed on Bungie's official site, where Parsons (pictured) published this mesage:
I want to personally thank Harold for his friendship, passion, hard work, and dedication in helping make Bungie the great company it is today. As a team, we celebrated many victories and weathered many storms.
To the players of Destiny, I want you to know that my number one priority, and Bungie’s, is and always has been to deliver great games that we can all share together. I believe that Destiny is a one-of-a-kind experience. I also believe you have yet to see our studio’s best work. My new role here at the studio will be entirely focused on fulfilling that promise.
Ryan had long been the head of the studio; his LinkedIn profile puts that date at 2000.