Windows 8 Release Preview runs fine on VMware Workstation 8.0.3 and free VMware Player 4.0.3
If you're running VMware Workstation 8.0.3 or even just the free VMware Player 4.0.3 (see also TinkerTry.com/freevmwareplayercancreatevms), you're all set, you have all you need. If you're using an older version, update first!
MacZilla even had success with a simple install under VMware Fusion 4.1.2, discussed at VMware here as well, and detailed step-by-step here (choose Windows 7, not Windows 8, for VM type).
Then visit Microsoft’s Windows 8 Release Preview ISO images site, making note of the license key that’ll you’ll need. I'd recommend you go with the 32 bit version for a bit better speed:
Next, do a straight-forward custom creation of a new virtual machine, telling the New Virtual Machine wizard that you have Windows 7 32 bit, and wish to install the operating system later. Now tweak the CD/DVD to mount the the ISO file for the CD/DVD, and remove the USB/Bluetooth support for the VM (makes things simpler). That's all, the install then proceeds just fine, quite quickly.
When the install is complete, go ahead and install VMware Tools, which installs and runs without issue as well. Now you'll even have multi-monitor support in full-screen mode, seen below: