But today, Microsoft's greatest challenge lies in enduring a year or so of Windows 8 growing pains on touch devices and while it continues to motivate developers to create Windows 8 apps against stiff competition from iOS and Android (which it is doing this week at its annual ).

And then there's that whole BYOD phenomenon.

"I think, in the end, Microsoft's greatest risk still lies in whether or not consumers and BYOD employees will like Windows 8 well enough to choose it over the alternatives for tablets," says Forrester's Johnson.