If Mozilla support Foo, then Google will probably support Foo (just as they're picking up support for asm.js now), and then Microsoft will eventually be cornered into supporting Foo as well. If Mozilla don't support Foo, people will say Foo is a Google-only standard, and Microsoft will use that as an excuse to not support Foo either. Every standardization effort, in the end, hinges on Mozilla.
The interesting thing is that Google has gone about the introduction of Dart in a scrupulously open way. They publicized the language early on it's design and implementation, they open sourced their implementation immediately on announcement and continued development in the open with input and contributions from all comers. The goal of the project is make it easier to develop better web apps. Now they've begun a standardization process.
So I expect Mozilla will oppose Dart, but they'll have to twist themselves into rhetorical contortions in the process. NIH is alive and well.
You aren't really addressing any of advantages or disadvantages of Dart.
* Can you live in a mostly Dart world?
* Are there performance advantages to using Dart that "just compiles to JS"?
Is this in reference to the DartVM or is there another feature? Isn't that turned off by default? I've only been casually watching this project and typescript so I don't know too much about it.
There is a fork of Chromium that we maintain, informally called "Dartium" that includes the Dart VM, bindings, an progressing set of dev tools, and native Dart-JS interop. Dartium is included in the Dart SDK, but only for development purposes.
How do you mean? Chrome support for Dart is the same as FireFox, Opera, Safari and IE>9 - via dart2js.
No browser includes a Dart VM yet.
The standardization means that the spec will be ratified, a conformance test suite will be created for independent implementations, and a process for evolving the language will be developed. It means that we can can compatible implementations, and that other individuals and companies interested in participating in the evolution of Dart will have an opportunity to do so.