After a new installation of Studio 6.0 EE, I am unable to see any Enterprise Server regions via the Server Explorer view in the Visual Studio 2008 IDE.  I can, however, view the servers using http://localhost:86.  I attempted a product "repair" via the "control panel/uninstall or change a program" but this made no difference.

The solution to this is to run "devenv /resetskippkgs" from the command prompt.