Michael Useem, previous CEO Trust speaker, Wharton management professor and director of the school’s Center for Leadership and Change Management, recently posted a blog highlighting what he considers the biggest leadership insight from the Nadella appointment: “Unequivocally, the enormous interest in who is going to run Microsoft is indicative of how much of an impact one great CEO, or conversely a not-great CEO, can have on the fortunes of the company. Leadership, and how much difference it makes, is the vital point here," says Useem.