Unfortunately Renee realistically has little chance of getting named. The stock would drop immediately. Major institutional holders wouldn't support the move as she's just not ready. Stacey would clearly like the job - he's been very visible and is well likled but board already has deep financial content. Brian is the obvious internal choice for a reason.
Over the years, I have been trying to observe at what age the typical F500 CEO retires. 62 is right about average.
He's filthy stinking rich. Why wouldn't he want to step down from such a demanding job, spend more time with the grand-kids, and "earn" a few million a year by sitting on a few corporate boards?