If you want to see the work being done done on this, http://people.mozilla.org/~jwein/ux-nightly/ http://people.mozilla.org/~jwein/ux-nightly/ has nightly build

If you want to see the work being done done on this, http://people.mozilla.org/~jwein/ux-nightly/ http://people.mozilla.org/~jwein/ux-nightly/ has nightly builds of the Australis UX overhaul. It's still hugely WIP though