I had WP back in the day. Bought an iPhone4 three years ago, and just switched back to a Lumia 930 as a personal treat. After a decade of fumbling the mobile market, I feel very positive about the moves MS is making to leverage its Office and Business Enterprise dominance into the mobile/consumer area. The moves to get a shared experience across all devices will just make so much sense for the millions of Windows desktop and laptop users to also opt into WP.
A big edge - IMHO - is MS's ability to offer the level of security MS can offer for mobile connections into enterprise servers. They have a stranglehold on the business side, and if they can provide the right tools for IT managers to ease managing WP devices with assured security (as compared with Andriod and iOS for example) companies will supply WP devices to employees, and that will spread the good news to the poor benighted who have not yet discovered WP.