Neowin has learned that a new theme, potentially destined for Windows XP, has leaked out of Microsoft and onto the web. The theme appears to have come out of a beta version of Media Center 2005, currently in testing.
The theme is not a substantially different incarnation of the existing of Luna, the current default theme for Windows XP. You can see the main changes in the screenshots below; one could describe it as being a "glass mod" of Luna.
As Microsoft knows, it is very hard to please everyone when it comes to themes. However, I think they can be reasonably certain that most people will like this new version of Luna. It is unknown whether this theme will make it into XP in the near future; Microsoft could potentially sneak it in at the last point with the soon to be released service pack 2 for XP.
Screenshots removed at the request of Microsoft