Okay, Windows 8 Installed - It's Useable
I did try one of the preview versions and pretty much stared at the monitor wondering how to use it and find stuff. After a week I deleted it.
In the following months I found some articles and You Tube videos that lifted the mystery. I'd like to say it is beyond me why Microsoft would make an OS upgrade so unfriendly to current users, but after a bit of instruction Windows 8 does seem to be useable.
Go ahead and try, but you'll probably need to find a how to before you know what's going on with the new OS.
Here's a couple of videos that will start to get you up to speed without missing the "start" button.
http://www.youtube.com/watch?v=_E1UxI5I_jo
http://www.youtube.com/watch?v=Q0EspF7mY6w