I'm going to go out on a limb and say that iSuppli is going to end up being wrong by a lot!
At first you may think... well, that's not going out on a limb. That's the common thought.
But I expect WP to hit 25% by then. Yes, as much as 7% more than iSupply predicts.
And I also think that will still place WP in a very close 3rd place. With iOS staying around 30% and Android holding 32%.
My completely 100% accurate predictions!
There will be a few growth spurts for WP.
Summer of 2012
Nokia ad push will take WP away from being an obscure OS to something most people will know about. Market share increase is limited because of the number of carriers the Lumia 900 is initially available in.
2.5% market share by the end of September 2012. But lots of increased mind share
December 2012 - January 2013
WP8 will have been introduced a month or two before this along with the new Windows 8 desktop and tablet OS. There will be a huge ad campaign by MS for Windows 8 and WP8 being members of the same "family." And tight integration will be very prominent in ads.
There will be another huge ad push by Nokia also. Versions of the Lumia 900 will have already been available on other carriers by now, and may be offered at reduced prices to make room for the WP8 devices.
Many people have contracts expiring and have the opportunity to try something new and fresh.
10% market share by the end of January
December 2013 - January 2014
Lots of interested people who were taking a "wait and see" approach have contracts that are expiring. We also see that businesses who have waited before upgrading to Windows 8 start converting a lot of their systems. Along with they, they buy handsets that are in the "family."
We see the new XBOX launch. The ad campaign also talks about tight integration and makes sure to point out the "family."
Integrates tightly with Windows 8 systems in the home as well as WP8 handsets. All in the "family."
22% market share by end of January 2014
December 2014 - January 2015
Windows Phone is pretty mainstream and popular by now.
MS Surface becomes "affordable" at under $2000. Is another member of the family.
25% market share by end of January 2015
Everything is a battle from this point on, with the 3 main ecosystems often gaining and losing every quarter.