According to figures from "Gartner":http://www.gartner.com/it/page.jsp?id=1848514 Microsoft's smartphone share was just 1.5% in 3Q 2011.
I think they're well positioned to take market share from smart phone leader Android.
I like Microsoft's stance on software updates to Windows Phones. They seem to be working well with delivering updates to "US":http://www.microsoft.com/windowsphone/en-us/features/update-schedule-usa.aspx and "global":http://www.microsoft.com/windowsphone/en-us/features/update-schedule-world.aspx phone customers. This avoids operating system fragmentation and allows developers to target the latest platform.
In comparison, Android has a "cumbersome":http://developer.sonyericsson.com/wp/2011/12/07/ice-cream-sandwich-from-source-code-release-to-software-upgrade/ upgrade process which involves heavy testing on the OEM and wireless carrier side. Outside of the Nexus lines of phones, Google has effectively outsourced the testing and integration of Android updates to OEM's and carriers.
As "previously mentioned,":http://julianyap.com/2011/12/07/Windows-Store-announcement-and-the-benefits-of-trials-for-apps.html I agree with how they have set up their Windows Store for apps. Having an app approval process also helps to "keep out malware":http://blog.mylookout.com/blog/2011/12/11/european-premium-sms-fraud/.
Nokia "announced today":http://press.nokia.com/2011/12/14/t-mobile-brings-nokia-lumia-710-to-the-u-s/ that will sell their Nokia Lumia 710 phone for $49.99 (after a $50 mail-in-rebate card) on T-Mobile. I anticipate heavy discounting of new Windows Phones in the coming year.
I have had a look at the Windows Phone OS and it looks like they really integrate social aspects well. I think that really counts in the eyes of younger users.
I also don't feel that Android users ("compared to iOS":http://www.changewaveresearch.com/articles/2011/iphone4s_20111201.html) users have much loyalty both in terms of the brand of phone and with the Android platform. Compelling features and marketing for Windows Phones when it comes time to upgrade could have them looking at Windows Phone as their next platform.