Engadget reports Mozilla visual designer Stephen Horlander showed off a mockup of a possible user interface for Firefox 4.
He outlines five portions of a screenshot teaser that'll get a much cleaner, more streamlined facelift. Our favorite takeaway is the singular app button for menu navigation. Several variations are shown, but if you ask us, we're currently fond of the setup above. As Horlander notes, the design's in constant flux, but what we're seeing is certainly promising.