Bob Nystrom, engineer with the Dart project, recorded a screencast of his presentation titled "Dart's plan to make it easier for you to build web apps".
From the video's abstract:
When we announced Dart, it kicked up a bit of a dust storm. In this talk, I discuss the challenges that Google and others face when building web apps today. I introduce Dart and show how its features were designed specifically to address some of those challenges.
You can learn more about Dart at http://www.dartlang.org and let us know what you think at http://dartlang.org/mailing-list. Enjoy!