Glad you mentioned that point. The distinction between '=' and '==' in most programming languages is a personal pet peeve of mine. I think that it confuses two separate issues: labeling a value with a name, and testing the equality of values. Terrifically confusing stuff if you're coming from algebra.

So, although '=' is available to make transitioning from other languages smoother, idiomatic CoffeeScript would use ':' for assignment, both within and outside of object literals, and would use 'is' for equality. Harder to make a bug out of:

    if x is y