Source: StatCounter Global Stats - Mobile OS Market Share

In five and a half years, Android has come from nowhere to dominate the mobile landscape during the first quarter of 2013, according to a new report from research firm Canalys.
Apple's iOS and Microsoft 's Windows 8 Phone together fails to beat Android Marketshare
Android share in Q1,2013 was 59.5%
Apple contribution was 19.3%
Windows Mobile OS increased its share to 18% ..
However both of them failed to unseat Android...marketshare in Q1,2013
The market – which takes into account smartphone, tablet, and notebook shipments – grew to 308.7 million, representing year-on-year growth of 37.4 percent.
Q1,2013 saw Android continuing the trend of increasing its marketshare, leaving Microsoft and Apple in dust During the quarter, Android was the operating system powering 59.5 % of smart devices shipped. Behind Android was Apple's iOS with a 19.3 percent market share, and Microsoft with 18.1 percent.