I'm currently testing Win 8 Consumer Preview and in short, if you didn't like the changes from XP to Vista/Win7, on a desktop PC using mouse and keyboard, you will not like Win8 because the user interface is designed more for portable devices with a touch screen.
Yes, there is a traditional DESKTOP user interface, but it's not a simple matter of selecting it and being able to operate as usual. The START menu is gone! You will struggle just to figure out how the shut down the computer. In fact, you need to be clarvoyant, or very lucky by experimenting to figure out how to operate Win8 because they've eliminated many of the visual cues that most people need to operate the system. It's the worse Windows user interface I've ever seen when trying to use the DESKTOP UI with a mouse & keyboard. In fact you can't even close an application by "X' ing" out anymore. EDIT: Correction, only some apps you can't X out. Not sure what the determining factors are yet.
On the other hand, for people that like tablet computers and smart phones, the METRO UI may suit them. For me, the Metro UI is more like going on the tour bus as opposed to being free to travel anywhere you like. It's the AOL model of computing aimed at novice users who will be satisfied to use the features hand picked & setup by Microsoft.
Ex-Microsoft Employee Launches 'Fixing Windows 8' Campaign | PCWorld
Bottom line, Win8 will not be greatly accepted by the business world and traditional desktop/mouse/keyboard users. With win8, Microsoft seems intent on abandoning that portion of their customers which might be due to the recent dramatic drop in sales of desktop PC in favor of portable devices such as tablets and smart phones. 2012 might be a good time to buy a new desktop PC with Win7 and also sell your MS stock!