As noted on the 3.0 Windows Default Theme Issues Wikipage, Firefox feels dated and behind on Windows. Especially Vista and Windows 7. These issues include absence of Glass, anemic purple toolbar color on Vista, tall and bulky UI footprint, element overload, inconsistent toolbar icon usage/style, lack of a tactile look & feel and perhaps too great of a divergence between the look on XP and Vista/7.
The proposed direction to correct these shortcomings includes:
* Embracing Glass: Toolbar and Tabs using Glass. Raised translucent buttons that are slightly glossy to meld with the toolbar. Raised 3D look to achieve tactile "feel".
* Neutral Tones: Overall neutral color scheme that can transition among platforms. Can remain attractive and slick without fighting for focus from web content.
* Hiding the Menu Bar: Hiding the menubar by default(on Vista/7) allows us to use Glass, free up vertical space and retain platform consistency.
* Page and Tools Buttons: Condense and trim existing menu structure into two buttons "Page" and "Tools". Similar to Safari and Chrome.
* Combine Stop/Reload: Combine Stop and Reload into one button. Reduces visual "clutter" and combines two buttons that have mutually exclusive functionality.
* Home Button/Tab: Remove "Home" Button from default toolbar. Move functionality to a "Home Tab" containing your homepage.
Source: OS News