A. Yes. Although the initial inclusion of the GPMC with Vista was designed to aid in the management of Group Policy, bundling the GPMC with the OS actually restricts how it can be updated as new features become available in the server OS. For example, the Windows Server 2008 GPMC supports Starter GPOs--support that’s not present in the Vista version.
When SP1 is installed, the system uninstalls the GPMC, and GPEdit with the default local group policy becomes the standard. The GPMC will be available as a download with the full functionality found in the server versions.