I am very happy to announce that Psscor4 is now available for download.  You can download it from:

Psscor4 Managed-Code Debugging Extension for WinDbg

This should have the same functionality as Psscor2 does but it works against the .NET 4.0 Framework.  Please let me know if you run into any problems downloading or using this extension.  I would also love to know if you have any feature requests for it.