Yeah - this has been posted way too many times. There was some work on significantly modifying the CoffeeScript compiler to add static metaprogramming (macros+more) but I don't think it's gone anywhere recently - https://github.com/fab13n/parsec-coffee-script.
The real point of the article was to draw attention to how extensible the CoffeeScript compiler can be. Jeremy talks about this when presenting the language and it's recently been used in a couple interesting ways like contracts.coffee (http://disnetdev.com/contracts.coffee/).