Today, we released Windows PowerShell 2.0 and WinRM 2.0 for pre-Windows 7 operating systems on Windows Update. This non-security, optional update is designed for Windows Server 2008 SP2, Windows Vista SP2, Windows Server 2003 SP2, and Windows XP SP3. Now it's even easier to install these great management tools!
Check out this post at the PowerShell blog for more details.
Program Manager | WS-Management