Dash is designed with three perspectives in mind:
The big Aim
Googles other Tools
Dash Clientsided & Serversided
Dart is meant to become the “Front-End” language in the World of Google which is able to be achieved from the Client but also from the Server (assumedly it goes in the direction of Node.js)
Will Dash run on the Server? Android? Yes, but short term we are focused on the client.
What happens with GO?
Go is a very promising systems-programming language in the vein of C++. We fully hope and expect that Go becomes the standard back-end language at Google over the next few years. Dash is focused on client (and eventually Front-end server development). The needs there are different (flexibility vs. stability) and therefore a different programming language is warranted.
Googles IDE “Brightly” – a Dart application?
It seems like Google is using a Cloud IDE intern which is going to support Dart and is written in the language – if we are going to see this IDE someday is not sure at all:
All in all: existing
Another interesting fact: One of the authors of the mail and the document about Dart is Brad Abrams who was the leader of Microsofts Silverlight Team about a year ago.