Andy Rubin, Senior Vice President at Google today tweeted “There are now over 500,000 Android devices activated every day, and it’s growing at 4.4% w/w”. He last tweeted about Android growth numbers in December when he reported that over 300,000 Android devices are being activated daily.

Though the number 500,000 activations per day is really impressive, but the most impressive part of the tweet is 4.4% w/w (week/week) growth rate. If Android continues to grow at this rate for next 26 weeks, Google will have over 1 million Android device activations per day by end of 2011.

We believe by end of this year two of the top three mobile platforms will stamp their authority on the mobile market. And the third platform will be decided in 2012 and 2013 with Microsoft, HP and RIM fighting to join the top three.