Now that Microsoft have made Windows 8 preview availible you are properly eager giving it a test run and in the age of virtualization you are properly going to install it in a virtual machine.
To save you some despair I will outline which virtualization environments that you can use to test run Windows 8 preview without to much hassle:
VMWare Workstation 7.x – You can not install Windows 8 Preview on VMWare 7.x.
VMWare Workstation 8.x – Windows 8 Preview installs and runs just fine in a VMWare Workstation 8.x vm
Windows Virtual PC 2007/Microsoft Virtual PC – You can not install Windows Preview in Virtual PC
Hyper-V – Windows 8 Preview installs and runs just fine in a Hyper-V virtual machine
VirtualBox – Windows 8 Preview (both the 32 and 64 bit version) installs and runs just fine in VirtualBox. You can download VirtualBox from here: http://www.virtualbox.org/ A guide for how to install Windows 8 preview in VirtualBox can be found here: http://www.winbeta.org/?q=guides/how-install-windows-8-virtualbox
By the way, you can also install Windows 8 in a VHD and boot from that.