Statcounter tells us something else
I'm not sure what kind of statistics Microsoft uses but for example in Russia which was mentioned as one of the Windows Phone success lands Statcounter statistics shows that WP share has been quite stable 2.5% for the last 6 months while iOS has grown from 16% to over 25% market share.
http://gs.statcounter.com/#mobile_os-RU-monthly-201209-201302
Statcounter puts WP to "other" category in many other of those mentioned success countries for example India and Poland, so it's hard to tell exactly how they are "kicking Apple in the core".