Sure, let's put everything in the Cloud ...Companies are already doing that with Windows anyway. Moving the big servers off site helps maintenance and upgrades, and Microsoft's high cost per server and user means anything to minimize the number of boxes is good.
The real problem with getting corporations off MS is the huge number of Windows applications that are baked into companies. Just moving these applications between "compatible" versions of windows is a huge issue that supports entire consulting companies. Moving these to non-Windows computers is going to take years/decades.