[scott_w]

"you're a web developer and should already be familiar with HAML, SASS, and Coffee"

That's like saying a web developer should be familiar with Ruby.

Unless you've made a conscious decision to use it, there's no reason to assume that you're familiar with the tools in question.

For what it's worth, I can see myself needing Backbone (or something similar) for what I'm working on, but there's no way I'll be using CoffeeScript.