You still have to ferry data in and out of Javascript to interact with the page. In the long-term, maybe language-specific bindings to interact with DOM APIs will become popular, but otherwise to get anything done in most cases you're probably going to expend enough effort on ferrying things in and out of JS land to negate the possible benefits of not needing to deal with a different language. I'd be surprised if many do it soon for anything more than a small high-performance core or for a large application that has a small DOM surface area (a game that just renders to a canvas).