I think what may happen is that there will be a minimum level of knowledge that has to be acquired across technologies (HTML, CSS, Javascript, and a backend lan

I think what may happen is that there will be a minimum level of knowledge that has to be acquired across technologies (HTML, CSS, Javascript, and a backend language), but beyond that we'll see more specialists with deeper understanding of specific parts of the development process. I would think that this would be the typical cycle in any information based profession (doctors, mechanics, etc.).