It looks not only me was feeling RJS templates are not all when comes to JavaScript generated from Rails. RJS works well when it has deal with AJAX requests. But when You need to generate some normal JavaScript code, based on some Rails controllers state it becomes hard with RJS (or at least I don’t know some easy way).
So there is Minus-R plugin (and its SVN repo) which allows to write Javascript templates like HTML from RHTML templates, just embeds Ruby in JavaScript. I have to try it, but judging from description… It is the Grail of JS generation…