Title should be "Windows Phone" not "Windows", unless OP believes that windows fate is tied to that of Windows Phone.
My Opinion: Killed Windows Phone? I doubt this. I personally believe that if the iPhone and Android did have such a strong foot hold(everyone going to them because of established user base) that Windows Phone would be doing much better. Also note that Windows Phone experienced its greatest increase in userbase this last quarter, time will tell how this goes in the future.
The only people i ever see talking down WP are those who have never used it. I personally use Android, but i am much more of a PowerUser then the avg consumer. Windows Phone is a great OS that is fluid and powerful, the only thing it lacks is a great establishment of apps.
With that said i am very glad BB10 is coming out, it looks to be very good for an initial offering. It needs work, but that will come. Lots of usability testing needs to take place though, raw advertising "feature sets" wont cut it.