That seems unfair on Vista. None of those themes came with XP out of the box (or worked at all without 3rd party add-ons/hacks).
I do still wonder why Vista (and 7) doesn't ship with the Luna theme, though. In situations where you can't use Aero/DWM I think the fallback theme in Vista is pretty ugly and Luna would look better.
(Luna Silver with the titlebars reduced to Win95 size, and the progress-bar and selected-item colours changed to something other than grey-on-grey, that is.
)