The way I remember things, the re-learning effort was not too burdensome in moving from Windows NT 3.5 to Windows 2000, later on to Windows XP, then a bit more of a familiarization jump to Windows Vista, followed by a smaller jump to Windows 7.
Compared with these, the move to Windows 8 is far from trivial, and will be a considerable time/expense burden on both consumer and enterprise users.
So my basic complaint is, why is Microsoft foisting the “metro” way of doing things upon all Windows 8 users even if they’re still only going to be using non-touchscreen PCs for some considerable time? Leave off letting us enjoy the metro mode when we get to a touchscreen device.
So far, I’ve spent 3 or 4 hours fiddling with Windows 8 options that have only gotten me a small way along the path of making Windows 8 desktop look, feel and act similar to Windows 7 desktop. It’s been an extremely frustrating experience, and I suspect that it’s bound to fail not much further along the path. This is NOT good news for all of those confirmed Windows desktop mode users out there!
Microsoft made the move from Windows 2000 to Windows XP not too difficult, with only a few things rearranged and/or hidden away in different spots. The move to Windows Vista was a bit more dramatic, but not unmanageable, Windows 7 was IMHO easier than Vista.
Based on my limited trials, but with a good “gut feel” of things after more than four decades in the industry, I reckon that moving to Windows 8 is going to be a real nightmare for desktop-only users upgrading from earlier Windows versions.
However I surmise that the Windows 8 experience will be quite pleasant and rewarding for all those users – possibly a very large proportion – who get Windows 8 preinstalled on a tablet device. This is where Microsoft is making a big gamble, I suppose. Time will tell how they fare.
What would a reactionary old codger like me know, anyway? … Then again, perhaps I'm not so technologically unaware as this other old-timer (it starts with a few sentences in German, no need for a translation, you will guess the meaning):