I just finished the PowerShell developer's conference and it looks like Microsoft is pretty serious about it. A number of Microsoft teams are developing enterprise products around PowerShell (such as Exchange 2007).
Microsoft is pushing the use of PowerShell snapins to be coupled with MMC 3.0 snapins. Basically they want developers to create PowerShell snapins that provide the functionality to administer an application and then create a MMC 3.0 snapin to provide the GUI environment (this would use the PowerShell API to run the PowerShell snapin).
This approach makes administering an application across the enterprise much simpler. Many I.T. administrators prefer a command-line over a GUI, especially if they can create a script to perform repetitive tasks.
I'm hoping that Microsoft builds PowerShell into Visual Studio. It would be nice to have such a rich command-line hosted within VS, especially if it has full access to the IDE object model (possibly an alternative to some macros). Unfortunately they were unable to give us any news about upcoming uses of PowerShell because the event was being recorded for distribution on the Internet and so it was not considered an "NDA" event.