I have a feeling once everyone gets past the "what I'm used to for the past 15 years" factor, Windows 8 will take off.
I've been using it for a while now, and while not 'perfect' (and that is highly relative), the new interface has its percs. Mind you I use it strictly on a PC without a touchscreen. There is a lot now I can do with fewer clicks and as a result, must faster. And the the responsiveness of the UI has improved more-so since Windows 7! And to be clear-- unless you've used it for a few months and have seen it, I can tell you first hand: I have- and it works as a desktop OS perfectly fine. In fact, its percs are growing on me.
I mean yeah, it's a diversion from what has been ingrained since Microsoft hit the modern UI with Windows 95. But once you get over that fact- the new, while different, is not in itself a failure. It is a well though out, fast, dynamic, easy to use UI.
All I can say if that if we keep an open mind to the likes of iOS or Linux, it's not so bad in principle to being open to Microsoft with a new UI. I mean, geez, I can remember a time I preferred Norton Commander (I'd like to see who remembers that, it was a DOS UI), over Windows 3.11.
I think most of it boils down bias. Which in the big picture, is definitely a part of the tech society. I've seen a lot of change in the PC world since i386 PC. My best advice is to keep an open mind. If you absolutely hate the new Start menu after having tried it for a while, there is nothing in Windows 8 preventing you from using the old one.