Seeing these types of experiments are always interesting but just like CoffeeScript it requires learning two languages instead of one [so you an debug] which makes it a hard sale. Why not just write clean JavaScript? I know many want to make JavaScript the assembly language of the web but JavaScript is so much more complex than assembly I'm not sure that's necessarily a good goal to have.

Granted I would love for more languages to be usable on the web; even if I thought JavaScript was the best language it's always good to have competition and alternatives. But I think that has to come through browser support. I wonder how feasible it would be to generate some sort of byte code similar to how Java and others work with the JVM.