We are still selling Windows 7 Pro machines, new from Dell with 3 year next business day, on site, warranty. Why anyone would buy Windows 8 is beyond me.
If MS don't get a grip real soon, Win7 might be the last version of windows with a big user footprint. They are driving businesses and people away, and Apple might just be the next big thing.
The two main drivers for retaining windows are:
Familiarity and the ability to run applications like SAGE.
New user interfaces make the next Windows as foreign as an Apple device so there's no difference between learning Apple or learning new Windows.
With multi OS development languages coming on stream and more web based applications, the strangle hold of windows is being broken.