Maybe rather than a new language, we should work towards browser "assembly" code. Lots of modern JavaScript development is in the direction of: write in language X, compile to JS. Would be nice if there was a lower-level target than JS
I think that browser "assembly" code, like Dash, would have to support this, particularly if it is meant to be an alternative to compiling to JavaScript.
Also, there's really opposition of having it implemented in other browsers, at least Mozilla vocally opposed it. I think that if they managed to do it via a plugin though, that could work.
While I do actually like Javascript a lot, I think we need to have more choices. When people point out Node as a benefit because "you can use the same language on the client and the server" I agree - but it misses the bigger problem in that, if you want to use the same language on the client and the server, you only have one real choice.