Your Office point kind of loses traction since I'd say the Office 2007 was a bigger change from Office 2003 than Windows 8 is to Windows 7.
Honestly Windows 8 doesn't change how people use computers that much. Most people use the start menu to ~search~ for a program. I.E. they hit start and begin typing. You can do the same exact thing with the Start screen.
Aside from the start screen, Windows continues to work in basically the same way it always has.
Who are these users and how do I get a job supporting them? I provide support to over 100 people and I've yet to find a single one who uses that particular feature. And now they're supposed to learn how to use "hot corners" (or whatever it's called)? Ugh.
I worked at a very Windows-heavy company until last year, and we were still on a very old version of Office when I left. (It was the pre-ribbon Office. 2005?) The reality was all the knowledge the employees had (not to mention their shitty macros) didn't transfer to the new version, so we simply did not upgrade.
The reason new laptops ship with a new version of Windows rather than Ubuntu is because people are used to fighting changes in their software, but they'll notice that they don't have "the real thing" when they buy a $13 Windows-only LED keychain charger and it doesn't work when they plug it in to their computer. Then they'll complain to their computer's OEM, and Microsoft will laugh evilly. (I don't really understand it. The amount of hardware I never got to work in Windows is approximately the same as the amount of hardware I never got to work under Linux.)
I wonder if Microsoft's numbers (which we're assuming they have and use) aren't skewed by the usage patterns that they create, with users taking the path of least resistance for the given options, which are themselves sometimes paths of a-fair-amount-of resistance.
For instance, I frequently switch windows in Win7 with Alt+Tab, but also dip into the task bar quite often to click the Word icon, then identify the correct Word document open, then move the mouse to the document... neither of which are particularly efficient.
The only approximate solution I can think of would be having a touchscreen above my F-keys to select apps with. I can imagine MS have no data on how well that would work.
I LOVE Alfred - it beats Spotlight hands down! The best equivalent I've used for windows is Launchy. Honestly Alfred has changed the way I use my Macbook :)
"I.E. they hit start and begin typing." -- people do that because the start menu in W7 has a text box that says "Search programs and file" and a visible caret telling them they can type. In W8 you do not get any visual clues to tell you that you can type to search.
It's improved in Win8. The results are sorted in some kind of MRU or frequency of use order. So the first time you have to look to not launch iTunes Help, but the second time iTunes will be on top.
Honestly Windows 8 doesn't change how people use computers that much. Most people use the start menu to ~search~ for a program. I.E. they hit start and begin typing. You can do the same exact thing with the Start screen.
Aside from the start screen, Windows continues to work in basically the same way it always has.