According to a latest research of Nielsen, Android ranks No.1 in smartphone OS marketshare and it holds 46.3% of the whole market. iOS, however, just occupied 30% in this research. (The figures are from Nielsen and the data comes from a research from 75000 customers which is beyond 18 years old.)
From the figure, we can make it clear that the market share of Android and iOS is continuously increase. On the other side, Blackberry OS, Windows Mobile OS and Symbian OS face with another downturn in the market. Unexpectedly Windows Phone 7 OS come across a significant growth after the release of Lumia 900 on CES 2012 and we probably can expect a larger space in market in future.
On the surface, Andoid OS has defeat iOS in the market. However, according to another research of the Demand for Mobile OS, the figure shows that Android is decreasing from 61.6% in October to 46.9% and the demand for iOS is increasing from 25.1% to 44.5%. Of course, it owe to iPhone 4S which covers 57% of the researched iPhones. Apparently people show great expectation for Apple.