Windows 8 is coming and, whether you like it or not, it's going to be big. Even if sales are dismal, there are still going to be millions of people using it. Understandably, browser makers want to be prepared. Google has a Metro version of Chrome essentially ready to go.
Mozilla is not far behind either. While Firefox for Windows 8 is not quite ready, Mozilla has a pretty good idea of how the "modern" UI version of the browser is going to look like. And it's going to look a lot like the Android version, apparently.
That makes sense, brand identity is important and, further, the Android UI has already been designed for touch-based tablets, there's no need to reinvent the wheel.
The top bar, with the AwesomeBar replacement, the back and refresh buttons as well as the tab manager button could be plucked straight from the Android version, you won't be able to tell the two apart.
Mockups of the Windows 8 UI have shown up from time to time. With Windows 8 fast approaching release and with Chrome already sporting a Windows 8 version of the UI, it's interesting to see how Firefox is doing.
For one, Mozilla opted for a totally different look than the regular desktop version of Firefox, unlike Chrome. It also took steps to integrate with the overall look of Windows 8.
For example, Firefox for Windows 8, apart from the elements common to the Android version, is sporting a bar that looks very, very similar to the one in IE 10, right down to using the same icons for the same buttons, i.e. pin site and so on. That's actually how Microsoft wants it, the company has much stricter UI guidelines for Windows 8 than for any of its predecessors.