The full release of PowerShell and the Windows Management Framework 3.0 has been released, I would suggest using it instead of the release candidate version you mentioned. You can find download links here: http://go.microsoft.com/fwlink/?LinkId=251995
The supported systems matrix is tighter than previous releases - you have to be running one of the following operating systems with the correct service pack level as well:
- Windows 7 Service Pack 1 (32-bit & 64-bit)
- Windows Server 2008 R2 Service Pack 1 (64-bit only, includes Server Core)
- Windows Server 2008 Service Pack 2 (32-bit & 64-bit)
Also note, if you have any of the pre-release builds of v3 installed, you will have to remove them before installing the officially released version.