Microsoft had a Mobile strategy, just not a Windows Phone marketing one.
Windows Mobile is dead, but its not from lack of trying from an engineering perspective, its from failure after failure from a marketing perspective, which has been a complete fc!k up from start to finish.
Its been badly marketed from Windows Phone 7 onwards and that includes larger mobile devices - Arm Tablets under the Windows RT Branding, Surface RT v Surface Pro. How the head of MS Marketing still has his job, I'm clueless - about time they kicked him into the long grass. The Marketing department need to anticipate more the effects of their announcements/naming strategies like Apple.
I'd be really surprised if Joe Belfiore comes back to a senior role too. Can't see it happening. A year away is a long time in tech.
Microsoft's best bet would be to work on a seamless global roaming 'whispernet' style 4G Mobile Data network linked to their Cloud Azure Services, but you can bet Apple already have this in the pipeline. ;)