Firefox 3.7: Initial Design Mockups Released!
Firefox 3.7 Initial Mockups for the Windows theme revamp.
These are NOT FINAL! THEY ARE ONLY FOR BRAINSTORMING/EXPLORATION!

- Embracing Glass Toolbar and Tabs using Glass. Buttons translucent and slightly glossy to meld with the toolbar. Raised 3D lookachieve tactile “feel”.
- Page Button: Connect the Page button to the left side of the tab area. Directly connected to the Page.
- Tools/Bookmark Bar: Connecting the Tools button to the side of the Window to emphasize the fact that it is used for customizing and changing the UI. Adding a button next to that to toggle the Bookmarks Bar which is turned off by default.
Source: MozillaWiki