Are there any potential to join both projects GWT and Vaadin into just one addon and put samples from test folder to a separate project (but not a test)? Anyways as far as I can judge it looks good, keep up doing a great job!
I decided to release them as separate add-ons to serve also the GWT developers. The samples are in test folder because it makes the testing of the add-on a lot more faster. I could add some more samples to the actual demo project though.