Google had their earnings call a little earlier, where they revealed their growth and revenue for Q4 2011. On top of this, Google CEO Larry Page said that there have been more than 250 million Android-based devices activated worldwide.
On top of this insane number, more than 11 billion applications have been downloaded from the Android Market. Considering that back in October of 2011, Apple said they had sold 250 million iOS devices (which include the iPad and iPod Touch), this means that Google have caught up to Apple. Keep in mind that Apple have a two-year head start in the smartphone market.
Google have activated 50 million devices since its last earnings report back in October 2011. It'll be interesting to see where these numbers sit at this time next year, Google have so many handset makers wanting to one-up each other, where Apple just slowly release their products. I think Google will really overtake Apple within 6 months, within 12 months we should see a nice lead.