Brain Bondy has posted on his blog information on the progress of getting a Firefox version specially designed for the Windows 8 Metro interface. The article does include a couple screenshots which look very similar to the mobile interface as currently being built on the Fennec XUL code (which Mozilla moved away from last year in favor of the native UI on Android).

According to the Firefox Roadmap a working prototype is expected for the 2nd quarter 2012. However, Alpha and Beta releases are not scheduled until the second half of 2012. Though at this time Microsoft does not have firm release date yet for Windows 8 other than mid to late 2012 (rumors say October 2012).

Brian R. Bondy: A working Firefox Windows 8 Metro prototype, status update 3