Interesting quote from an Intel Support page:
"Windows 8 has native in-box USB 3.0 driver. Intel is not releasing a specific USB 3.0 eXtensible Host Controller driver for Windows 8."
In the left margin of that page whose URL you provided, there is feedback form for us to fill out.
May I suggest that those who are dissatisfied with the current device driver provided by Microsoft fill out the form to let Intel know that it'd be in its customers' interest to release one for Windows 8?
What do you guys think?