Ashley: I know you're probably sick of me pointing to this, but I would really love for you to read these two articles and then tell me if this is not a technology worth considering
Given the number of people here criticising us for "depending on third parties too much", I am extremely wary of adding any additional technology dependencies in to the C2 workflow. Even if Haxe works pretty well, we could still get shafted by compiler bugs, missing features and unoptimised parts that kill the performance. In particular I think Stencyl got burned by some of these types of issues. I'd rather stick with HTML5 - it may not be perfect, but it's improving fast and has some huge players backing it, such as Microsoft and Google.
slowly replacing parts of the engine with asm.js code?
IMO this is a much better idea than writing native exporters. I do want to do this eventually, but it still means rewriting a big part of the runtime, and probably breaking compatibility with all existing plugins. So I want to do this eventually, but it would probably come post-C3 release.
Also regarding native exporters - one of the reasons C2 is $129 for all exporters and not $999 is that we only have one codebase we need to maintain. All that extra engineering work would probably push the price up to another level. And "all exporters for one price" is a really nice thing about our licensing IMO.