I've downloaded the RC1 of Windows PowerShell and I'm fairly impressed.  Why should you use this?  Imagine being able to access .NET assemblies and programming constructs from the command line or in batch files.  Also imagine a more "scripty" vbscript.  That's what powershell is.  It's about damn time too after spending a few years in a Unix shop and seeing what can be done in scripts I was getting a little tired of batch files.  PowerShell blows away any current scripting environment.  There's real error handling using Trap.  Where other shells pass and parse text, PowerShell passes objects and you can reference object properties by name.   I've been spending the last week  getting aquainted  with the features and will be posting a few scripts soon.  I've seen about a billion WMI scripts but very few showing basic interaction with existing executables.  Once you get the hang of it however, it's simply great.