So far it's not clear cut. When Angular.dart was announced, some people claimed that it would become the default version, and that features would be backported

So far it's not clear cut. When Angular.dart was announced, some people claimed that it would become the default version, and that features would be backported to the JS version. There were strong rebuttals from googlers, but IIRC none of which from the Angular team itself. For v1.2, the Angular.js team has rushed the backport a controversial feature[1] from its .dart counterpart three weeks before release, months after the first RC was released, breaking the meaning of a release candidate. :-/ -- 1. the underscore prefix to make $scope fields private.