The readme.txt of the Chipset drivers 18.104.22.1681 already lists that Windows 8 is supported. The Intel website itself is not yet updated for Windows 8 (not possible to select win8 as filter, etc). I assume that this will be done when Win8 is released to the public.
Windows 8 also comes by itself with chipset drivers. I had no problem with Win8 x64 RTM and my DZ68BC board.