At last years Google IO Ray Ryan presented a collection of architecture recommendations for GWT applications based on what the team found best practices when developing the new AdWords application at Google. This guy took the effort to transcribe the complete presentation and even included all the slides.
The presented technologies were: MVP, Display Interface and EventBus.
Now Google has published a new introductory article covering everything mentioned in Ray's presentation and a lot more.
This is a must-read for every developer who wants to seriously proceed with GWT application development :Large scale application development and MVP