I've been watching the whole Coffeescript thing for a while now, and even dabbled in it a couple of times. I just cannot figure out why you wouldn't just write Javascript instead? With the plethora of libraries around nowadays, writing 'browser neutral code' is just as easy - if not easier - in plain Javascript.
Personally, I find it a pain in the arse to read, it constantly looks like something is missing, and I don't really want to learn a new syntax and stuff to get to where I already am..
I had a very basic example here, but the forums don't keep formatting... https://gist.github.com/3736194