Hi Kevin,
Thanks for responding.
1. The Window 7 RC (7100) _is_ my host computer. It has Aero enabled (translucent).
2. All 7 of the Experience options, including Themes, is checked (allowed), in the RDC client on my Vista computer.
On the Vista computer, viewing the remote desktop on the Windows 7 computer, with the Personalization window open, there's a message at the bottom of the Personalization window that says: "One or more of the themes has been disabled by Remote Desktop Connection settings".
I don't know how or where to enable it.