"Microsoft Windows PowerShell is a new command-line shell and scripting language that is designed for system administration and automation. Windows PowerShell lets IT professionals and developers control and automate the administration of Windows and applications. Also, Windows PowerShell is built on the Microsoft .NET Framework."
I also have Windows PowerShell 1.0 installed. It seems to have become installed among a bunch of other Windows Updates earlier this month. I doubt if I will ever have any use for it but like Limpy I wonder if I should remove it via Add Remove Programs or jut leave it be.