I really can't wrap my hands around windows 8, it just isn't familiar and / or intuitive. I personally think it is a HUGE mistake by Microsoft. Much of the reason users don't switch platforms is the usability and learning curve, and windows 8 WILL require a learning curve.
Look at history.
Microsoft has had a track record of having some really solid OS's...and some clunkers.
For sake of illustration...I'll start with Windows 95....since most here won't remember 3.x or DOS versions.
Win95a...short run, basically all excitement was over the new platform.
Win95b had a VERY long run, got quite stable.
Win95c and d...basically extensions of b....
Windows NT 4...didn't hit home users, and small percentage of power users in business.
Win98....did OK with home users, wasn't adopted in business environment.
Win98SE...did much better with home users, still wasn't adopted in business world much.
Windows ME....horrible, was an abortion of an OS, rushed out at the last minute because the plan for a home user version of Windows 2000 never completed in time.
Windows 2000...This first rehash/update of NT technology didn't do well with home users. Started getting popular in business networks, still didn't hit home users much.
It took Windows XP to take the solid full 32 bit platform to home users....basically their first big taste of NT technology. Can certainly call XP a success.
Vista....similar to 2000, the next rehash/update of NT technology. Stumbled a bit....took a few service packs to get performance better, but too late...garnered a bad rep.
Windows 7..an update of Vista, similar to XP though...finally brought popularity to this platform. I'd call it a success.
So now based on the prior cycle laid out before us...we are due for another next generation...birth..and a general lack of acceptance.