Mike, I know you saw my comments about this on Facebook, but others here probably didn't.
I'm actually really impressed that Microsoft did something so bold, and finally discarded the "start menu plus desktop icons" layout that has prevailed since Windows 95. Yes, you can get to a desktop in Win8, sort of... but it's clear that Microsoft's UI designers want the user to start thinking in different directions in terms of how they interface with their applications and settings.
I've been a huge critic of Microsoft for their conceptual and design stagnation. Somewhere around 2000 or so, they really seemed to lose the drive to make great products, and just seemed to want to sell a lot of software. Yes, there's a difference!
As Mike hinted, I would strongly caution that the Win8 user interface and interactivity experience is very much changed from Win7, and indeed all earlier flavors of Windows. The best comparison I can make is the conceptual leap from Windows 3.11 to Windows 95, and the introduction of the Start Menu. If you're familiar with earlier versions of Windows, you will probably find Win8 at least as foreign as you would MacOS or Linux. Some things are familiar, but overall it's an entirely different way of accessing your files, applications and settings, and switching between one thing and another.
I can see how this maybe end up being a revolutionary improvement in the user experience, but the first time you sit down to use Win8 you might be stumped about how to do some fairly basic things. I've been a corporate IT Manager for nearly 20 years, and I'm comfortable with a whole range of operating systems.
After I installed Win8 on a PC I'm refurbishing at work (not my main workstation), one of my co-workers came over to watch -- and he's a real tech enthusiast, who builds his own PCs from scratch every couple of years, and knows almost as much of the nuts and bolts stuff as I do. Both of us were stumped, more than once, about how to do fairly basic things or get from one place to another. The experience left him more than a little concerned, because he's in the process of building a new PC now, and he had taken the plunge and ordered Win8 for the new machine.... now he's wishing he had waited, not because he doesn't want to try Win8, but because there appears to be a huge learning curve and he doesn't want to feel like a fish out of water, trying to start using this new PC that he's excited about.
Honestly, if I had only one primary computer workstation, I would not put Win8 on it at this time. Not until I had more of a chance to explore it on somebody else's machine, get more comfortable... experiment, ask questions, figure out sticking points, and look up solutions.
Those of you who have more than one machine you can use for your important work will probably do OK installing Win 8 on one of them. If you get to a place where the changes are frustrating, you'll be able to switch to your old machine and get your work done.