IDC released the number of mobile phones sold in Q3 2012. Totaled at 181.1 million, the majority was made up of Android, with 136 million, or 75% of the market share. The iPhone moved 26.9 million units in Q3 with 14.9% market share. Blackberry pushed 7.7 million units but is showing a negative downtrend year-over-year. Symbian moved 4.1 million, mostly in developing nations, and is showing a downward trend as well.
When you look down towards the bottom you see Windows Phone which sold 3.6 million units, or 2% of smart phone sales. However, they are growing rapidly at 140% year-over-year change. This upward trend looks promising, but if Windows Phone 8 sales don't take off this year. Nokia and Microsoft will be looking at another Zune. With Windows 8 introducing the tile interface to the masses, I believe the market share will grow nicely over the next year, maybe to 5% or so, taking most of its newly acquired market share from Blackberry and Symbian.
Android and iOS will hold onto their share and easily keep Microsoft and Nokia out, but Blackberry and Symbian's downtrend gives Windows Phone the chance to grab up a little more market share next year.
There is a lot more information at the IDC site.