Jobs, who yesterday, was immediately given the title Chairman of the company's board.

On Thursday, Apple , formerly the chief operating officer, as the new CEO.

"It's going to be extremely difficult for the new CEO to go his own way and succeed in a context like this," said Peter Cappelli, a professor at the Wharton School and the director of its Center for Human Resources. "It's going to be difficult [for Cook] to do anything different with Jobs as chairman."

It's unclear what Jobs' role will be as chairman, but reports yesterday and today, including from long-time Apple observer of the Wall Street Journal, hinted that Jobs will continue to be involved in product development.

Most transitions of this kind -- when a CEO moves to the chairman role and a new CEO is appointed -- are fraught with trouble, but Apple is a special case, Cappelli said, because of Jobs' iconic stature in the industry and his perceived value as the firm's product development guiding hand.