Typescript seriously needs to start getting its act together. The roadmap shows they're making some headway on these new es6 features, but it feels like they're trying to both accept it for es6 output mode, and for es3/es5 output mode. This means further delays, during which period we can't use them at all.

And because typescript != javascript, we can't use any other tools, either. TS is duplicating the 6to5 efforts, with little to show for it.

If you use TS, right now you're stuck with es5. It's starting to itch.

I wish they'd prioritize the es6 features in es6 output mode and let me worry about converting that to es5.