I've seen the links come by. If you follow news sites such as Winbeta.org or Neowin.net it isn't hard to find your way to the iso images for Windows 8, Visual Studio 2012 or even Windows Server 2012. But will you download and install them?
There's quite a few risks involved... While these images look genuine, you can never be sure somebody hasn't slipped a rootkit or faulty drivers into the images you're downloading. When you install Windows 8, you're prompted to associate your Microsoft Account to your installation. To download certain drivers from Windows Update and to install certain features, Windows 8 requires your installation to be activated. Since these images use a generic product key you're not able to do so at this time. Unless you use a Volume License Key and an untrusted license server.
I've been contemplating downloading and installing it. I've decided to hold off just a little longer. In another week the product keys and images should make it to MSDN. I can wait just another week.
That will be my mantra... I can wait another week :).