A look at Apple's management changes and several key executives' futures; sources say Mike Rockwell has considered leaving or taking an advisory role next year (Mark Gurman/Bloomberg)

Mark Gurman / Bloomberg: A look at Apple's management changes and several key executives' futures; sources say Mike Rockwell has considered leaving or taking an advisory role next year — John Ternus, Apple Inc.'s next chief executive officer, is up against a major challenge as he settles into the role: retaining top talent during a time of historic turnover.