When Disney's Bob Iger announced last year that Thomas Staggs would eventually take the top job at the company, it looks like they had their succession plan nailed now. But this week, Staggs suddenly announced he would be stepping down, taking everyone by surprise. No one is quite sure what happened in the intervening year, but some suspect Disney's board didn't embrace Staggs in the way he would have wanted. Right now it's unclear who will take his place. Theories range from Facebook's Sheryl Sandberg stepping in to Bob Iger remaining in place longer. Disney likes to promote from within, but now they may be looking at an outsider to come in and run their company. Either way, Staggs' departure is a black eye for Disney, which works hard to avoid any kind of public scuffles.