It has kept them on 7, but if they need to upgrade, more of them will just go to Mac and be done with Windows.
Windows 8 is an unmitigated disaster.
Business’s won’t move, too much of a pain, but individuals, yep, they will decide they are done. Not all of them, but more than would have prior to Windows 8.
I just don’t see it. Vista didn’t send people to the Mac in droves and neither will 8, and 8’s a much better OS.