Is there anything about MS really still to say?
I could try add to the discussion, that IMHO currently the biggest problem with MS' mobile future is Google. Google is quite deliberately trying to minimize it's presence on Windows Phones and if Microsoft can't handle the situation somehow (by paying money), that's going to cause problem for Windows Phone.
Here's some recent and current issues:
* Google blocked the WP's YouTube app. So, currently,
Windows Phone doesn't have official and working YouTube app.
* Google was seriously discussing of
dropping Windows Phone's Gmail Calendar & Contacts sync support (Exchange ActiveSync). This has been delayed until the end of this year.
* Previously, Google's app advertising platform supported iOS, Android and WP. They released
an update to Admob which dropped the support for WP (this has been then added as a beta feature).
* Google extended Analytics to apps. That includes Android and iOS apps, no Windows Phone.
* Chromecast has iOS and Android support, but no Windows Phone.
* Google Wallet has iOS and Android support, but no Windows Phone.
* GMail has official iOS and Android apps, but no Window Phone.
* Google Maps has official iOS and Android apps, but no Windows Phone.
Google has previously blocked Windows Phone users from accessing Google Maps with Mobile IE. (I'm not sure if this is still effective.)
And so on. Google owns the Web and if they block Microsoft out from their services, it's not good for Windows Phone. But I don't think there's anything that money couldn't fix.
The reality is also that Microsoft has the most platforms to cover if they want their services to be used with mobile phones & tablets:
* Apple (mostly) only creates apps and services for their own devices.
* Google makes sure that their apps and services work with both Google's and Apple's devices.
* Microsoft have to provide their apps and service for their own system, to Apple's devices and to Google's devices.