"Microsoft will announce its rebranding of its "Windows Azure" cloud operating system to "Microsoft Azure,
...
The rebranding makes sense, given Windows Azure isn't all about Windows. Azure customers can run Linux in virtual machines on the operating system. Azure users also can run Oracle databases and middleware, and use non-Windows-specific development tools, including Java, Ruby, PHP and Python."
Google is driving such naming (everything Google xy),
so Microsoft needs to reinforce its brand...