Hey everyone, I'm evaluating Win8 64 bit Pro as we speak and here are my preliminary opinions.
Originally I've tested the OS only in a work environment and it did not feel adequate to the needs of a business. So now I am testing this for a home environment. Clearly the OS is designed for entertainment purposes. Even in the onset it is noticeable that there is a bit more optimization for speed. The browser natively installed is a lot more efficient than on Win7. Software installs are tempermental at the moment. After installing the NVidia drivers software I would have an issue with the system hanging on the login screen. The new GUI is annoying for starters but as I can see there are some perks to it with the constant use of the OS due to the more popular apps being splashed into the main interface.
I did my own type of bench test of the speed of the OS with loading of SWTOR a MMO that would drag down this machine on Win7. It ran noticeably faster the very same machine with Win8.

I so far find it to be useful for entertainment purposes but still need time to see if the OS is really going to play out well for anything else.

I'd like to see if anyone else agrees or disagrees with my initial thoughts.