Don't have a horse in this race but with regards to desktops, the number of Macs Apple has been selling and Linux are passing itches on the butt of Windows. They are totally insignificant on the desktop. That will remain unchanged unless Microsoft really screws up. I would have though that impossible, but however unlikely, it is possible. In a theoretical sense
Naw, I don't see anything changing in the short term. People will complain about the new Windows, and a lot maybe not buy it, but computers last a long time and they'll just wait for a version they do like to purchase. Too much work on Windows that don't work on other platforms. The only platform that might overcome Windows sometime in the future is the Internet.