It looks good, but I don't see any demos that involve graphics. How usable is Vaadin for graphics?
According to this example: http://demo.vaadin.com/Coverflow/ It seems like you can add custom widgets easily. In this app they started using a Flash Widget for custom graphics. I'm not a GWT developer, does anyone have any experience adding custom GWT/Vaadin widgets to your applications?
Book of Vaadin http://vaadin.com/book has a whole chapter on this. Also the Vaadin Eclipse Plugin makes getting started with adding new widgets trivial (just "Add New Widget" and it creates a widget stub for you)