NOTE:
At the end of the previous step we used the super-source tag; someone may have noticed that when you use super-source you end up with an eclipse project with errors: the project compiles with GWT and works without problems but eclipse signals errors in all the super-source'd classes (actually because package names are not correct).
To find the best solution for this annoying situation, last week I asked on the google-web-toolkit google group. Actually the full solution is harder than we can afford in this post but you can find here the thread; in our demo-project without serverside component and without tests the first response in the thread is enough, but for a bigger application some care is needed.