When last we hear Google speak on the number of Android devices activated per day, Larry Page declared the number at 550,000. That way way back on July 14th. Now analyst Michael DeGusta predicts that the number could reach as high as one million devices worldwide every day before the end of October. That’s a growth of nearly double in less than ninety days.

Even conservative estimates put the number of worldwide activations at at least 1,000,000 a day by December. Any way you slice it, it’s an incredible milestone for an operating system that’s about to pass its third birthday (if you go by retail hardware). And of course, it’s a heck of a statistic to come out the day before a certain big announcement.

The number of Android activations, i.e. the number of smartphones, tablets and other devices that sign in to Google for the first time on any given day, isn’t exactly, well, exact. There’s a significant number of Android devices that eschew the Android Market and other Google services, not to mention older phones that are hard reset or loaded up with new software. But as a metric of growth, it lines up with other statistics nicely, including the all-important market share reports.

At last count, Android had a whopping 54% of the market share among “connected devices” (smartphones and tablets combined). The next closest was Apple’s iOS with 28%, followed by Blackberry at 13%. Windows Mobile and Symbian were each rated at just 1%. Both Android and iOS are expanding, while all other competitors are in decline. Apple still leads the individual device race with the iPhone’s 13% share and the tablet market with the iPad winning over 80%.