Emerging markets
And low priced devices are coming under attack by the Lumia range, particularly budget models by the unknown smaller ODM's. (Loads are coming out at the minute since MS ditched license fees).
Personally I see iOS at top end, Samsung have the lions share of mid and high end outside of iOS, with HTC taking the leftovers at mid-market and Lumia taking a decent chunk of the budget ene, particularly in emerging markets. Sony are mad carrying on as they are, and Sammy would be nuts to drop their devices (which are excellent).
I wouldn't discount WP in the BRIC's and other emerging markets and the West's budget segment, seems to be a lot of traction currently.