Microsoft tried this with ActiveX. Deja-vu, all over again. http://technologizer.com/2010/09/16/the-unwelcome-return-of-...
In Google's words: "The goal of the Dash (Dart) effort is ultimately to replace JavaScript as the lingua franca of Web development on the open Web platform"
I will never support Google's walled garden. Dart is a pathogen.