Firefox 3.5 was released just a short time back, however Mozilla has already begun work on Firefox 3.7 the next version of the browser.

Mashable spotted the new theme mockup screenshots of Mozilla in the Mozilla Wiki.

The new features in the theme will include;

1. Embracing Glass: Toolbar and Tabs using Glass. Buttons translucent and slightly glossy to meld with the toolbar. Raised 3D lookachieve tactile "feel".
2. Page Button: Connect the Page button to the left side of the tab area. Directly connected to the Page.
3. 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.

Here are the screens from the mockup created for the default Windows Firefox theme.

What do you think of the theme for Firefox 3.7? Remember these are just initial mockups and lots of things may change in the final version of the product.