A faster VM is the real goal of Dart, it's faster than JS, it even benches faster than Java in some cases. It's gotten that fast in a lot less time with a lot less code, because it was designed from the start to be optimized for the VM. It's a different take on producing a faster VM for the web. However I doubt it will ever make it past chrome so what's the point. If you just target chrome you can use Portable Native Client if you need performance.