I came across a great add-on for PowerShell, PowerTab which you can find at the power shell guy's site. This provides you with intellisense when accessing the .NET framework in PowerShell. I know that PowerShell in Windows 7 has a script editor, but I haven't used it so I don't know if it has intellisense or not. I will update shrotly in that regard.
If you find yourself writing any scripts that access the .NET framework, or if you occasionally touch the framework from a powershell session, you will find PowerTab useful. Head on over to http://shrinkster.com/1bgc and check out PowerTab.