I don't think that the problem is figuring out Windows 8 (something that anyone could do given enough time), but, rather, the real problem is unwillingness to buy. Having heard from friends and the media that Windows 8 is radically different, any remaining interest is dissipated on sight of screenshots or a demo computer in-store.
That said, my parents, when actually confronted with it, were fine; they weren't huge fans, but using the new interface wasn't a problem after they adjusted.
My parents could use their new Win8 computer quite well. But then, after seeing lots of tutorials, trying things for a long time and exploring all the new interface, they asked "Can't you really put a start menu on that thing?"
It's not the end of the world. But it's not a good interface either.
That said, my parents, when actually confronted with it, were fine; they weren't huge fans, but using the new interface wasn't a problem after they adjusted.