Android has come a long way, reaching 400 million units in the market, and yet it keeps growing very fast, and it's now at an astounding 1 million new device activations every single day. That means 30 million new Android devices every month, or 365+ million new Android devices every year.
If Android's growth remains stagnant at this number, there could be close to 600 million Android devices in the market by the end of the year, and if it keeps growing a little, there will be over 1 billion Android devices in the market next year. Amazing. Google says it's not showing any signs of slowdown yet. But I figure in US things should get more stabilized around 50% or so market share, but the global market share is still up for grabs for Google.
Especially in emergent countries like India and China, Google is already reaching 70% of the market. If Google gets to keep that kind of market share over the years, that means hundreds of millions more Android devices will appear in those countries, and developers should be working with billions of Android devices a few years from now. Android should truly become the computing platform of the world then, with the biggest installed base (should be bigger than Windows by then).