Stephen Horlander has updated the Mozilla wiki with initial mock-ups of Firefox 3.7's new theme for the Windows platform. Although it's nothing more yet than a mock-up it does show quite a big and exciting change.

Also do note that what is currently called Firefox 3.7 might be relabeled to something else, so see it as a future improvement somewhere after the current 3.5. At first the new look looks a but like what we've seen with Chrome and Safari, but applies a more polished look as seen below:

Highlights:

• The toolbar and tabs are using Windows Vista and 7's Aero glass like theme, meaning it's transparent and will color with your appearance settings.
• The navigation buttons are translucent and slightly glossy to meld with the toolbar on all Windows platforms, with or without Aero. The shape of the buttons looks a bit like Chrome, but better.
• A page button on the left, where Chrome and Safari place it on the right. This should expose page related functionality (needed for the omitted menu bar).
• A tools button, similar to Chrome and Safari is placed on the right, this will allow access to UI options (needed for the omitted menu bar).

As you may have seen some standard stuff is missing in the mock-up, but that's why it's a mock-up. The scroll bar, status bar and personal bookmarks bar will probably re-appear in as (default) settings.