It normally isn't news when IT people move from company to company, but there are times and circumstances when personnel movements do attract attention. Microsoft's announcement that Kevin Johnson is leaving for a position with Juniper Networks is noteworthy.

Where this particular departure becomes interesting is in the role that Johnson held within Microsoft and the activities he was involved in prior to his departure. As the head of platforms and services within Microsoft, Johnson was responsible for some of the biggest assets managed by Microsoft, including the Windows operating system, the MSN Instant Messenger and associated network, and Windows Live email (previously Hotmail). If this wasn't enough, the division was also responsible for Microsoft's online advertising and search endeavours. With the recent high profile focus from Microsoft on these latter two areas as well as significant coverage of Windows Vista and plans for Windows 7 it would seem that Johnson held one of the most important jobs within the company.

In addition to the above responsibilities, Johnson was reportedly one of the key individuals associated with Microsoft's repeated bids for Yahoo, all of which were ultimately unsuccessful. Coupled with search and advertising performance that were falling short of company goals and Johnson's departure suddenly looks very conveniently timed. Correlation doesn't imply causation and with Johnson heading off to take the top job at a major networking hardware company he is certainly continuing to move up the corporate ladder.

Random speculation can be fun but Johnson leaves behind a division that wears the brunt of what many consider to be a mangled Windows Vista, an online services department that has lost almost half a billion dollars in the most recent reporting quarter, an advertising services portfolio that is still significantly behind Google despite the 2007 US$6 billion acquisition of aQuantive, and multiple failed takeover bids for Yahoo. Yahoo's acceptance of Carl Icahn representatives on their board might be seen as a partial victory for Microsoft but it probably came after Johnson had made his decision to leave the company.

Post Johnson's departure, the Platforms and Services division will be reformed as the Windows/Windows Live division and an online services division, with separate heads reporting directly to Steve Ballmer (three for the Windows/Windows Live division and one for online services). This split represents a recognition of the key functional difference between online service offerings and operating system offerings, though the inclusion of Windows Live with the operating system division suggests that Microsoft is still trying to integrate online services tightly into the core operating system.

With so many recent changes within the senior ranks of Microsoft, the question is how long the old guard will remain in place and what sort of direction the company will take once they finally depart from active control of the company. So long as Bill Gates retains some level of control over the company this will probably never happen, but just as Apple performed significantly differently without the hand of Jobs, Microsoft might very well be a completely different company after Gates and Ballmer.