Where I work, it is all Macs (100 people or so), iPhones and iPads - everything is Apple. 100 person company is tiny (by Microsoft standards), but consider 100 companies with 100 people each - suddenly it is not small anymore. Add to it some mid sized companies, and departments from big companies that slowly replace windows with Mac/Linux, it looks pretty bad.

Microsoft's death won't be sudden like Myspace's. It will be slow and will spread over decades. Unless wake up. Purely from a engineering view, they are still a formidable player, and they invest in R&D more than anyone else. If they want, they can still make things happen.