The future of GWT is going towards Dart

What is the future of the JSCompiler and GWT? JSCompiler and GWT were already on a merger path. This effort gives us a direction for that unification around the Dash language. We will actively support teams for a long time on the current generation of JSCompiler and GWT and provide fantastic co-existence and migration tools to Dash.
We intend for existing Google teams using GWT and JSCompiler to eventually migrate to the Dash compiler.
-- Google