@fanbaby: Personally, my concern is that, regardless of whether you do or don't like Javascript as a language, having only one language to develop in is a step back from other platforms that are designed such that anyone can write a compiler that converts whatever language they like (or a new, ground-breaking language they invent) to a bytecode or native code. Choice (and room for innovation) > no choice.

However, the GWT (and for F#, WebSharper) approach of compiling languages to JS itself is interesting. I'm worried that, because JS is designed to be a high-level language rather than a compiler target, it may not work as well for the latter purpose. At least, compilers targeting JS still seem to be a lot rarer than compilers targeting other platforms, which makes me wonder why. But I haven't given it serious thought, actually one of my plans for the near future is to look into this more (and delve more into studying compilers in general).