I sort of like the idea, but think I'd rather just have a CoffeeScript version of EJS. It's hell on my shift key but I still _like_ HTML as it is, after all these years.
I like HTML too, but when I took a look at ECO i thought wow, that's a lot of `%` signs... Then I started thinking about all that big corp JSP I wrote a lifetime ago.
Taking a second look at CoffeeKup made me appreciate what the project is doing, clearly abstracting away useless syntax with the same good'ole functions.