We've created a GWT library, initially for our internal projects, that has proved quite effective for us and easy to onboard even for GWT-unskilled developers. We've put it on
https://github.com/turnsk/gwtmvp in public domain for the community to use.
The two main benefits (as we see them) are (1) pure HTML UI with UiBinder-like binding support and (2) built-in MVP framework on top of the GWT history mechanism. More details are available at the github link above.
Looking forward to any feedback and/or new ideas you might have.
Tomas.