Bastion was released on the Google Chrome store :) Jus sayin'... good example of a great game being played on a browser. No idea if it's HTML5 or not, but it does show how far browser gaming has come.
Anyway, back to my hidey-hole...
This. Bastion actually runs on NaCL (Native Client), google native run time for Chrome. I think that the best way to get an EXE exporter would be NaCL. But that would involve: Rewrite the entire runtime in a language that NaCL supports (currently C++ and C, more to come like C#). Then from this code base make exe exporter and NaCL exporter that would run on the browser. The problem is that currently only chrome supports it. The advantage would be : One code, like C++ , run on NaCL and every place that supports C++, that is everywhere. My hope of this technology is that: It get's universally supported on all browsers ,and gets support for C# because i hate C++. But this may take time. So the result is: Exe exporter won't be coming anytime soon most likely.