Microsoft is going to need to really get their butts in gear if they ever want to have a presence in the mobile phone market. If they could make the entirety of 32-bit and 64-bit Windows apps work as well as they do on the PC, that would certainly help Microsoft. They should probably start pushing Intel to focus more on power efficient x86 processors. That way, Intel's processors can compete directly with ARM processors, while providing Windows users with access to the millions of apps, both new and old, available on Windows PCs. Also, Microsoft should not stop people from using non-appstore apps, since doing so will discourage users and developers alike.
Of course, Microsoft has been trying for years to get their operating systems on handheld devices. They've never even managed to compete with PalmOS, let alone IOS or Android. I remember my mother getting a Windows-based phone around the same time Windows Vista hit store shelves. She now uses an iPhone, and is unlikely to go back.