I like the basic idea, but my hope is that we can go the other direction and bring more interesting languages to the client side. I know this is done to some ex

I like the basic idea, but my hope is that we can go the other direction and bring more interesting languages to the client side. I know this is done to some extent using JS or Asm.js as a compile target with a whole bunch of existing projects. But it would be great to see this really move forward. It seems like CoffeeScript did this rather successfully, and with source maps, the debugging story is getting better too. Any reasons why this might not be a more compelling future than the "JS everywhere" vision?