There was an announcement not long ago about 700.000 new activations every day. And only new devices are counted. If you buy a used phone it is not counted. It is really impressive.
I read in an article that the economic situation is making people choose cheaper Android phones rather than iPhones. Android is also a lot more popular than iPhone in Europe. But also the more expensive Android phones are competing directly with iPhone Phones. Galaxy S2 have sold millions and millions last year.
It's funny though, I believe Nokia is still the largest mobile phone manufacturer. Their share is constantly decreasing but still large. It's weird because I rarely see Nokia phones these days. A friend of mine bought the latest Nokia model, simply because his previous phone was Nokia. And the OS is quite ugly compared to iOS and Android. My brother bought a Nokia because it had the best camera on the market, planning to use it in his work.
But if you walk into a phone store these days and listen to some customers you will notice how important brand loyalty is. An older man walked in to buy his first smartphone, knowing nothing about them he wanted a Sony Ericsson because that's what his old phone was. An Android based SE is completely different from an old dumbphone SE. Sticking to a particular brand when you move to smartphones makes no sense if you have any knowledge about Android.