Started development using
Google Web Toolkit which in my opinion will be one of the major development tools for enterprise applications.
Let me explain from Oracle UCM point of view, in UCM services can be consumed using JSON that's by adding IsJson=1 at end of the URL, even if you created custom services you can consume them using JSON too. Now using GWT you can build your vertical solution which calls UCM services and display results and takes actions. In that way you will gain great benefits, like concentrating on user interface, build easy to use application, and lightweight too which will attract customers.
I recommend you to take a look and consider it seriously as another point of view for development.