After a healthy alpha (and pre-alpha) period, Mozilla is taking the mobile version of Firefox 4 to beta on Android and Maemo this week, promising improvements in stability, performance, and functionality. Actually, this represents a shift in branding for Maemo, where Firefox 1.1 has already been gold for some time -- but odds are good you're going to want to upgrade in any event, since this new version nets you the so-called Layers framework that aims to improve scrolling and zooming responsiveness. As you might expect, you get built-in Firefox Sync -- basically making this a superset of Firefox Home -- and support for HTML5. Makes that ol' N900 look a little shinier, doesn't it? Follow the break for Mozilla's announcement video.