Originally Posted by Jawshco
Mindy Kaling and BJ Novak are working on a new show called "It's Messy," (about a young female Doctor) and as you mentioned Paul Leberstien is leaving to write and work on Dwight's new show. So that's at least 5. (6 if you count Carrell who is already gone). Wouldn't surprise me if Jon K & Jenna Fischer didn't renew their contracts.
John Kransisky and Ed Helms are currently in negotiations on new contracts. And BJ Novak, as far as I can tell, will be back. He's not leaving for Mindy's new show. Maybe I'm wrong on that. But everything I've seen online indicates that BJ will be back.