Yup, same as spiller: running Win 8 Pro x64 through Dreamspark Premium. Excellent OS. No problems (other than unsigned driver issues, which have been a problem in x64 windows since Vista) and loving the new start screen. Windows Store apps are elegant, and although they are very feature bare they start fast and allow really quick access to the information you want. Took me five minutes to set up the Mail account with two Gmails and a Yahoo, but have since switched over to a unifying Outlook.com account to simplify things. I also use the Tweetro, Wikipedia, Messaging, OneNote MX (best app out yet, and amazingly usable), IE10 (Metro and Desktop. Amazing performance I have to say. Kudos IE team!) and (less often) the Store, Calendar and News apps. Excellent job MS!
Since the Developer Preview I've been running nothing but Win8, and the transitions between versions have been almost painless. One small scare led me to transfer all of my personal files to the cloud (via SkyDrive) and I have to say it was the best move I ever made. The SkyDrive Windows Store App (versus the desktop client) is now a 'Share Charm' target, meaning not only can I save to the cloud, but I can save a 'shared' version with any email address, negating the usual 'middle-man' of having to save the file locally then go to the SkyDrive site and manually choose to share it.
The sharing and Devices charm I also use a lot, surprisingly. It's amazingly simple (read, four clicks) to send a cute cat picture to a friend, and even less if you email that person often (their contact gets 'pinned' to the share charm), or I can post that link/picture directly to twitter or Facebook through the People app and Tweetro. The devices app houses my printer, and the new printing pane is amazingly simple and usable. All excellent job, Microsoft!
So far I'd give the OS a 5/5, but the implementation a 4.5/5 because even Microsoft's own Windows Store apps are so rudimentary that they're almost (but not quite) useless.
Have a nice day,