I've been thinking about this for a bit, and doing some research on how to minimize Metro in Win 8. There are several shells available already, including a very interesting one for which we've created a subforum. It is called Power8.
It seems to me that there will be 3 yrs of improvements under the hood of Win 8 that may or may not ever be transferred to Win 7. This alone gives it some cachet. And at $40 for the Win 8 Pro version? This is the least expensive pro version of Windows I've ever heard of. So that is some incentive too.
If you are dead set against the Metro interface, then I believe there will be some good alternatives available which will make this operating system useable on the desktop. I don't like the style of Metro, or Microsoft's obvious strategy of moving us towards apps that they can control and profit from any more than most of the members here, but I believe we will have options to sidestep it by the time Microsoft finally releases the operating system.
So, I'll probably chip in forty bucks for the upgrade version and see if I can make it work to my satisfaction. I seriously doubt it will come close to my main computer or even my second one, so I may have to scrape some parts together on a third just to play with this operating system.