"XX million copies of Windows 8 shipped."
"Windows 8 sets record for [carefully worded phrase relating to sales volume]"
...et cetera.
Essentially, Microsoft will make a concerted effort to assure potential customers that Windows 8 is something that is being accepted. I guess that's no big surprise.
Will Windows 8 add significant or measurable value to the user currently using Windows 7, Vista or XP? I would argue that the value added for the vast majority of users will not exceed the paltry $40 upgrade cost.
In 10 years, will Windows 8 be viewed as another Windows ME or Windows Vista (i.e., minor updates that were largely viewed as worse than their predecessors)? I don't know, but my initial guess is 'yes.'