There's been a steady flow of betas for Firefox's Android offering and now the official Twitter account promises something "big" on the way next week, along with this image. The size declaration plus a lack of updated features (specifically Flash support) on tablets so far has us looking there for something new, although the image clearly shows a phone with the words "Fast. Smart. Safe." Also curious is an update for the Firefox beta on Android today which the Twitter account also admonishes those looking for an early preview of next week's news to check out. Finally, there's the timing, as Firefox's main browser rival Chrome has been rumored