We're currently working on a series of addins and refactors to make the form builder more user friendly. For starters, the UI was changed a bit to be less of an eyesore, as you can see on this snapshot:
Also, work has started on the following subjects, that have been waiting for a while:
Inserting elements in a layout: You can see this on the screenshot. You don't have to worry any more of getting the elements in the correct order, now you can add an element to any posible position in the current layout (as long as it obeys the laws of that layout. ie, you coulnd't add something to the right or left of an element on a vertical layout)
Work on this subject will continue to allow already dropped UI components to be moved, by right-clicking on it and selecting "Move"
Validation attachment: Validations can be added since a few posts back, but so far, the only validation available to add is "Not empty". Also, there wasn't a representation of these validations, either on client or in server side. These are some of the things that I'll be working on next week.
I18N of labels and such: These aspect of form design is something yet to be properly defined. Most fields on a form will have an explainatory label, and so, will be needing a way to configure that label according to the user's language. For such, a display will be added (and accessible by right clicking on a text and selecting "Internationalize") to show different flags and associate the proper message for each language.
L10N helpers for labels and such: For the same reason as i18n, l10n might be a delicate subject for forms that should show currencies and number punctuations.
Event handlers: Every change and every action a user takes on the form, either in HTML or any other display, will fire different kinds of events. By right-clicking on different ui components and selecting "Event handling", you will be able to manage actions to be taken for such events, that might go from a communication to a server to the full client-side updating of the form.
Using RestyGWT for client server communication: This framework allows developers to create simple Resteasy clients in GWT, and it will provide a much needed cleansing to the client server communication layer of the form builder.
For any doubts or questions, feel free to comment below
Cheers from Argentina