I had a lot of issues getting Super Dev mode to work with IntelliJ. This question, and my answer below, are to document how to do this, for anyone else who might come across thi
@Click Upvote 's answer is not right. You don't have to replace the host html page is script tag's src attribute. Or you'll find out every GWT RPC request will send to port 9876(on which the code server runs) instead of the web server port(8080 for example).
there is a post talking about this problem here.
by the way i'm using gwt 2.6.1 and Intellij 13.0.1