I'm a java guy who tried GWT and I got disappointed when tried to integrate to my current IDE, the eclipse project creator is so narrowed that I couldn't work it around easily. The winner lang-framework will be something very similar to GWT. Imagine use swing directly in the browser without all the jvm load and plugins, etc. Today with javafx, air and silverlight they are trying to do that. Something standard and open will come up, but thanks to companies like google who research and releases products like gwt that objective is nearest each day.