[btford]

> the development of important features stalled for AngularJS as the team was busy working on Dart version.

Not true. Google grew the team. Take a look at the activity on Github. The velocity has been consistently high throughout the development of the Dart fork: https://github.com/angular/angular.js/pulse

If there was some important feature you wanted, you are always able to submit a PR yourself. That's how open source works.