It turns out that Windows 8 is largely the same as Windows 7 as far as drivers go, so most Mac/Boot Camp users on Windows 7 waiting for Apple to release Windows 8 drivers can just go ahead and install Windows 8 on an existing Windows 7 partition.
If you are upgrading from anything earlier - Vista or XP - then you will have to download the latest BootCamp drivers - aka Windows Support Software - from Apple. The easy way to do this is to run Boot Camp Assistant from within OS X, and tick the box for 'Download the latest Windows support software from Apple'.
If Boot Camp Assistant fails to download the drivers for you, then you can still get the by following instructions on /p682/download-bootcamp-drivers.
If you've removed OS X from your Mac and have to do the download in Windows, then you'll also need this page /p860/opening-a-bootcamp-driver-download-on-windows-7-or-8-with-7-zip
A couple of people have reported that the drivers don't work 100%. I'm not sure which models work completely, all I can tell you is that for my Core2 Duo MacBookPro everything works fine, including the camera, backlit keyboard, and screen resolution.