According to the Rails 3.0 release notes at rails.info the ActionView form helper with the :remote option set to true will add a "data-remote" attribute to the HTML tag. It think it is good that the old-style inline JavaScript has been removed, however, I do see some problems with the new approch:
1. It's not vaild HTML. 2. It doesn't follow the HTML attribute convention. There should be no hyphen in the attribute name, and the value should repeat the name instead of "true". It should look something like this: 'remote="remote"' (or the short form 'remote' in SGML-based HTML).