Well, as a person who owns an Android tablet and who upgraded to a Windows Phone from an iPhone, I have to say that I think there's a huge amount of value in what Microsoft is offering. Their OS license costs to OEM's are actually very cheap (I've read reports that it's anywhere from $5-15 per handset; it's a fair bet that Nokia's getting the best deal of anyone), but one thing that's become abundantly clear of late is that Microsoft's OS is *dramatically* more modern, fast and fluid than is Google's. Don't get me wrong--I like Android. It's got a lot of solid capabilities, but using it just feels like I'm using an antiquated device from a bygone era. The static icons, the sluggishness by comparison with WP8. I'm using bone-stock Android 4.2.2 Jellybean on a Galaxy Tab 2 10.1, and its performance is nowhere near what I get on my Lumia 920. Absolutely everything about the Lumia's OS looks and feels faster, smoother, cleaner and more modern. Sure, I can also customize my 'Droid tab to give me certain kinds of info right on my home screen via Widgets, just like I can get with Live Tiles on WP8, but it's nowhere near as ubiquitous nor as easy to use. Too, there's no "Deep Linking" inside of apps for Android (or iOS, in fairness).
Add to that the experience of using Windows 8 on a modern PC is simply *fantastic* (yes, I realize it doesn't hold up quite as well for users still using non-touch PC's, but frankly, I've had no trouble adapting. Windows 8 has replaced OSX as the primary OS I use on my Macbook Pro, and it's just so superior, even without touch, that I can't see myself ever booting into OSX for anything but the rare OSX-only app), and as it spreads and becomes more familiar to a larger audience, it's a fair bet that it WILL influence people to try a Windows Phone, too. In point of fact, in the past 6 months both my mother and sister switched to Lumia 920's from iPhones and aren't looking to go back. I also have a cousin, a friend, and several classmates who've upgraded from various flavors of iOS and Android devices, and they're all very, very happy with the choice.
I realize that change is hard for a lot of people. They see something new and they balk, and it might take them years and a lot of prodding before they finally switch. I clearly recall the loathing people had for the Start Menu when it was introduced in Win95/NT--I and just about everyone I know HATED it. 5 years in, and you could hardly live without it. I recall, similarly, that Windows XP started off with slow sales and a lot of hate--from users, because it worked so differently from the 9x versions of Windows, from developers, because coding for it was very different, especially after SP2 locked the OS's security down--and from IT types, who hated its "candy looking" UI. Twelve years later, what do we have? People who still sing the praises of XP, which has only recently been supplanted by Windows 7 in total installed base.
If there was ever a version of Windows that was going to kill Microsoft, it was Vista. It was so bloated, so confused and failed to deliver on half the features they'd touted in the 5+ years of its development. It was sluggish even on fast computers, and it wasn't until SP2 that they sorted out a significant portion of those issues. And yet, Windows 7 sold like mad and is much beloved.
Long story short: We're in a transition period, and Microsoft is in very little long term danger. They know how to play the long game better than just about anyone, and they've proven it time and time again.