In my experience with Windows Azure, Microsoft seems to be moving deliberately slowly. They build a small solid foundation and add more features when they're ready. Azure didn't have AutoScale until recently. I'm sure WinRT will keep growing.
Windows 8.1 is opening a lot back up but I will agree that MS shot themselves in the foot by making it as "simplified" as it is. It's nowhere near 1:1 with .NET or even Win32 at this point and that'll likely take quite a bit of time, likely well beyond the "mythical version 3".
I feel they absolutely have to release new version of Windows or at least the API every year. It has to get very close to 1:1 or a lot more people will start abandoning ship. I know personally I was more neutral and borderline annoyed at the WinRT change but I think 8.1 is reviving some enthusiasm I lost. I believe they're heading in the right direction it'll just be a matter of getting there as fast as possible to keep my interest. It's not a very pleasant feeling when you think that you picked a poor choice by sticking with .NET as things start to fall away. I keep looking for WinRT projects to start picking up steam but they're pretty much non-existent in the Atlanta area, save a very select few. I'm really hoping 8.1 starts to change that.
Spoiler alert: WinRT is completely DOA.