Dart looks pretty good to me actually. But it's from Google and that scares me at this point.

ES6 also gonna be pretty good but it's still not released and I think it'll be at year 2030 or something.

ECMA plans to sign-off on ES6 in December 2014: https://mail.mozilla.org/pipermail/es-discuss/2013-November/...

But browsers are already rolling out some ES6 features now: http://kangax.github.io/es5-compat-table/es6/

"For ES6, 2014 should be a year of cleanup and minor refinement."

A whole year. I'm not gonna pretend that I have any idea how this process works. Still, what kind of a cleanup takes a year? Cities recovered from natural disasters much faster.

ES6 is going to be awesome, but the advatange I see in Dart is its optional typing system and included libraries.

Cool! I've been looking at it for some projects. Can you link or maybe just explain what you use it for/with?

I'm using on intranet projects, making web 2.0 applications is a breeze with Dart, in pub.darlang.org you can get a list of projects and libraries using Dart.

Single page apps or more traditional approach with HTML generated on a server?

Single page apps.