Just to address some of the concerns in this thread:
- I know the US requirement is annoying, but it's just the way it is. Often US employees for legal reasons or others are tasked to do business only with others in the US. It may also be possible that they can help you out getting started with Windows Phone development, but on the condition that you're in the US. I agree they're missing out big time: US visitors are a minority of our overall traffic, so presumably also a minority of overall C2 developers. However, it's not our battle to fight, so for the time being I'm afraid this opportunity depends on where you live. On the other hand if you are a US citizen it may be an interesting opportunity for you.
- I know IE doesn't support WebGL, but currently we have disabled WebGL on all mobile devices in the C2 engine because our testing has shown it's either slower on mobile or causes bugs and crashes. It's still a work-in-progress on mobile really. So you're not losing any performance - no other mobiles are using WebGL.
IE for mobile is also the only mobile browser I'm aware of with a GPU accelerated canvas 2D natively in the browser. So you may get pretty good performance anyway.