I only mention the virtual machine very briefly in a list of things that come with Dart (batteries included rock) as I didn't want to loose/confuse the reader since there are no browsers that come with a Dart VM yet (except Dartium which is awesome for development).

As mraleph already mentioned the Dart VM is very useful for the instant-feedback development experience that you get from working with Dart.

It would be awesome to see it in Chrome or other platforms going forward but having it from the start is a big plus for day to day development and for the people building infrastructure on top of Dart.

There are also people who do exciting stuff with the VM in node-like scenarios.

I personally can't comment on that because we haven't looked into that use-case yet (our backend is in Python and App Engine does not support Dart yet) I'm very interested in the VM and I guess we'll see some interesting things in this area going forward.