Oh C'mon, Seriously!
Microsoft is already diversifying itself. They do eHealth are big in government business and all is funded with a rock solid Windows base. It is so obvious they are going to want antitrust compliance to avoid a split.
Going strong as current, the fortune some-hundreds will continue to pay up software assurance, windows upgrades, even more Microsoft software - just because the Redmond strategy works that way.
Example,.. Exchange 2007 is the last version to support "Public Folders" if you want you can stay at Exchange 2007 for some 10 years to come, yet - Microsoft ist pretty much the only company that breaks out a feature completly in an upgrade. Oh yea "Public Folders" are okay, but I need the new bloat of SharePoint. Then I guess people are luckily paying for another Windows server, for a SharePoint server, for some hundred SharePoint CAL's, and Staff Training. This is the Microsoft way of business.
People don't necessarily want to have a choice, that is why Apple and Microsoft do good business and Linux on a desktop is still for the dire crack if the preconfigured stuff is not sufficient (ie. you need to install more software)