According to a discovery by Softpedia on the Mozilla Wiki, the user-interface for Firefox 3.7 will be redesigned to give make use of the Windows 7 features and also make it visually appealing on both Vista and Windows XP.

Mockups for the Firefox 3.7 UI in Windows Vista and XP can be seen below (click to enlarge):

As the message on the wiki says, these mockups are nothing but only for exploration and brainstorming so there is a good chance that the final UI for Firefox 3.7 would be pretty much different than these ones.

Here are some of the important features of this UI as mentioned in the wiki:

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.

Right now, the only information provided by Mozilla is that it is planning to incorporate this new design in Firefox 3.7 and no roadmap for the release of this version has been so far provided.

Its definitely a clever move by Mozilla as Firefox has everything in it, speed, security and now all what we need is a stylish new UI.