THe problems that Dart solves as of now will probably be fixed in ECMAScript6 and TypeScript as well. Also the speed of Asm.js being implemented into V8 will definitely boost V8's speed.
I wonder how Netflix would perform with using Dart with the DartVM. I reckon it would be faster than Node based on benchmarks I've seen. Chrome DartVM support is right around the corner ;)
For Dart, it wasn't fully valid. The problem was that they used the 32-bit VM on a 64-bit machine. Of course, the Dart team is working on fixing the number boxing on the 32-bit version that resulted in the poor performance, but the 64-bit performance would've been better, as outlined in the article.
I was think more about Server-side speed(Dart vs NodeJS in server-side performance). Dart has already proven that its faster than hand-written JS with dart2js in client-side.
Nice, nice, Im a 15 year old web designer that started working on node 2 weeks ago, but then I was introduced to Dart and it really intrigued me. I have basic knowledge of JS and Im taking an AP Java class in school, so its a win/win for me xP