Feels like adding a layer of Java inside JavaScript. Google should instead improve the internals of language and leave syntax similar to JavaScript.
If they want web developers to use it, they need to improve JavaScript itself, not to try to shove another Java inside a browser. I think they are in the opinion that JS spec is too flexible to optimize and want to get something more static with some declarative overhead so the VM can optimize.
Google's Latest and greatest language..Compiled with python,java and XML
http://code.google.com/p/dart/source/browse/branches/bleeding_edge/dart/compiler/dartium.gyp