As part of the Visual Studio Team System setup, we are using a System Health Check tool to verify that all the servers involved in the setup are conifugured properly and are in a good state. The System Health Check tool uses WMI to query remote servers and check their state. This works great until the servers are configured to use IPv6. WMI RPC's (Remote Procedure Calls) over IPv6 are not currently supported on any OS other than Vista.
So if anyone out there is using WMI RPC's, you may want to test your setup or app in an IPv6 environment to see if you run into any problems.