Win-8 does give people a reason to upgrade, because it is part of Microsoft's "the same interface anywhere" strategy. Look at these three screen shots (Win-8, XBox, Windows-phone):
Anyone notice the similarities? You should, because they are exactly the same. Remember, the XBox (under the hood) is just a plain, old fashioned PC. Mine has recently been downloading a LOT of updates. I suspect the OS has been upgraded from the XP variant it used to use to a Win-8 variant.
MS now has 4 device families (PC, tablet, phone, and game console) running the same OS.
As a developer, I've been inundated with material from MS (to the point that it's becoming spamming) trying to get me to start writing apps for Win-8 (including offers for free training).
Microsoft's strategy seems to be "buy an app once, use it anywhere." Get an app for your phone, use it on your XBox (the kinect provides the "touchscreen"), your PC, or your tablet.
I'm not sure how this will work out, Microsoft's dominant position in game consoles gives them an advantage over their competition. The only question is: can they get their app store up to speed quickly enough to leverage their advantage?
Cool. Since I don't own an XBox and can't imagine buying a phone that might blue-screen in the middle of a call, I won't have to worry about ever upgrading to W8.
Do people really want their PCs “DUMBED DOWN” to an app mentality? Microsoft is gambling it is yes. If enough fuss is raised, then Microsoft might bring the classic start menu back for Windows 8.