I don't think I'd find this that useful. Coffeescript already has jslint support, and I'd only want to do minification right before deployment since minified JS is harder to debug.
ready.js won't overwrite your javascript, that would be stupid, it compiles your javascript in another folder. When you're in dev, you simply link to your uncompiled js. When in prod, you link to your compiled js.
My point was there's no incentive to have your js be compiled continuously. (I already have a deploy script, adding minification to that wouldn't be hard.)
