Anyway, I installed the Developer Preview on a netbook last year and it was transformative - the machine went from the typical clunky netbook experience to being a useful computer. I found myself looking for excuses to use it instead of my regular machine, rather than kicking myself for having wasted money on it. So I jumped at the Consumer Preview and installed it over Win7 on my primary machine. The process was smooth and it kept all my settings from Win7, right down to the smallest detail. All my hardware is still working, no problems with device drivers, and all my software continues to work well, too. I spent 10 minutes or so customising the Start Screen, exactly as I had done with the Win7 Start Menu when I bought the machine. I also created the custom shutdown and restart icons and put them on my desktop and Start Screen.
From that point on it has been an overwhelmingly positive experience for me. Most of it is as close to Win7 as Win7 is to WinXP, so it is not the entire new interface that you might think it is. Once you are in the desktop, the only hint that it is not Win7 is the missing Start button. But once you start to work with it, you realise that there are a lot of changes and that they are all for the better. Because it kept all my desktop shortcuts and applications pinned to the Taskbar, I almost never have to use the Start Screen which makes it easy to forget that it is a new OS. But I find myself looking for excuses to go and use some of the Metro apps just for the hell of it. The Reader app, for example, is an excellent alternative to Adobe Reader. It is very basic but it lets you read PDFs without any clutter. I like it. I like the email app too, it is much better than checking Hotmail in my browser. IE 10 on the Metro side is less successful but the full desktop version is also available and it works as you'd expect (although I use Firefox).
I'd recommend it wholeheartedly to anyone, you just need to go into it with an open mind and be willing to embrace change. After just a few days you will have to drag me kicking and screaming back to Win7.