Microsoft is a company in a constant state of evolution, and today this is perfectly demonstrated by a huge shakeup at the top. Satya Nadella wrote to employees to explain a number of changes to the Senior Leadership Team -- including the departure of Stephen Elop. The former Nokia CEO and Nadella "agreed that now is the right time for him to retire from Microsoft". A question that can be heard echoing through the company is "did he jump, or was he pushed?" Mark Penn is also leaving the company to form a private equity fund. The reorganization additionally sees the company dividing into three distinct teams to "deliver better products and services our customers love at a more rapid pace". In an email Nadella reveals that golden boy Terry Myerson will, in effect, be taking over for Elop, the man once destined for the top position at Microsoft. The existing Operating Systems Group and Microsoft Devices Group are being combined into a new division called the Windows and Devices Group.