Having freshly switched from Android and Apple to a WP8 L928, I can agree that WP8 is lacking in some areas. I can also agree that they are lagging a bit to get features out that most have been crying out for. However, I don't see how WP is going to fail in the US.
WP did a good thing by making an OS that is different. When Android came out, it had the same 4 standard icons at the bottom and icons all over the screen as Apple - the only difference was it was open, it had a separate app drawer, and the G1 had a physical keyboard in addition to a soft keyboard. It took Android a while before it got apps in it's App Store that made people think twice. I love Android, don't get me wrong. But what plagues it is the fragmentation. And yes, fragmentation is still a big problem. I believe the one thing that keeps Android going strong is the fact that you can root them and do what you want with it. Rooting kept me with the latest OS. Rooting allowed me to change things around. Rooting allowed apps you wouldn't normally get. But that was all because someone had that device and was willing to support it. So the rooting community is almost like another OS in and of itself because Android puts out a new OS, it gets released by the manufacturer, and then you have to hope a developer cooks something up. Otherwise, you're still left waiting.
With Apple, you either stick with what you have or jailbreak it.
So the rooting community keeps Android going strong and Apple has it's faithful fanbase. WP needs one of those two. And while I agree they need to start implementing some features that Apple and Android have - I want them to take their time because, well, if I wanted Android or Apple, I would get one of their phones.