Johnson is among a legion of former Microsoft executives who have gone to lead other companies. He joined Juniper Networks, the computer networking gear maker, five years ago. Last month, he disclosed plans to resign as soon as a replacement is found. Johnson's keen familiarity with Microsoft -- he once presided over its Windows and online services division -- is a definite plus. Whether he can breathe innovation into the company, something it sorely lacks, is an open question.
Investors cheered news that Microsoft CEO Steve Ballmer will retire, but there is no obvious successor in line.