That's over 2.1 million phones every week and over 9 million phones every month. Four months ago, in August 2010, Google CEO Eric Schmidt announced that Android activations passed the 200,000 per day mark. Apple then countered by revealing in September 2010 that it was seeing over 230,000 new iOS activations every day.
The devil is in the details though: Rubin specifically says that the number is 300,000 phones activated each day, which means tablets and other devices running Android are not being counted. Back in September though, Apple's number referred to iOS activations, which means it includes other iOS devices like iPads and iPod touches.
In sheer activation numbers, Google is thus clearly winning. The company is soon going to be activating over 10 million Android phones per month, and the growth doesn't seem to be slowing.