I think the browser dev tools (esp. Chrome's) show some promise in that regard. For instance with Workspaces you can mess around in dev tools and save changes d

I think the browser dev tools (esp. Chrome's) show some promise in that regard. For instance with Workspaces you can mess around in dev tools and save changes directly to your source files; with a tighter integration between the element inspector, source view, and js console they could achieve some real visual programming power there (for instance being able to jump from a component rendered in the UI directly to its code and representation of current state).