updated 11:05 pm EDT, Wed October 24, 2012
Clean installs of the new Microsoft OS should work fine
Virtualization solutions provider Parallels has issued a "critical and urgent Windows 8 service advisory" recommending that users not perform an upgrade to Windows 8 form an existing Windows install. Potential side effects of a botched upgrade include damage to the virtual machine and data loss.
The release is brief, and does not address the specific modes of failure of the upgrade. The Parallels advisory says "We're working hard on completing our testing of the Windows 8 upgrade, and will inform you via in-product notification when you can successfully upgrade to Windows 8." Updates on the status of the Parallels revision can be found on the support pages for the application.
A full installation of Windows 8 without migrating any applications or data "should work just fine" according to the service advisory. Parallels does recommend that users upgrade to the very latest build of Parallels Desktop prior to creating the new virtual machine.