Windows Management Framework 3.0 (Includes PowerShell 3.0, WMI & WinRM for downlevel Win7, 2008, & 2008 R2) is now available here
http://www.microsoft.com/en-us/download/details.aspx?id=34595. For those getting a
"This update is not applicable to your computer" error when trying to install it

Update your Microsoft .Net Framework 4 first. Get it here
http://www.microsoft.com/en-us/download/details.aspx?id=17851
After the update the install should complete fine.