Whether it's asm.js or PNaCL or something else, it seems that we are headed towards a future where the client part of web applications is crafted with compiled languages rather than JavaScript. That would be closer to the way mobile is now, with the exception that applications are discovered through a browser. It's starting to feel as if the JavaScript renaissance that we are having is taking us to a place where actually crafting web applications with JavaScript is factored out. That would certainly change what it means to be a front-end web developer. Maybe it will be that JavaScript will still have a place with very simple document-type content, while heavier applications will be made with compiled langauges. It's going to be interesting to watch this unfold.