There are a lot of node/npm modules that aren't ES6 friendly... unless they pull in and shim out cjs/npm modules, then it will still be some time before it's really useful.

Setting up a build watcher in Grunt/Gulp/etc is really worth the time savings, especially if you use Live Reload. I make a change to a file in vim, and the page reloads with the new build.

I think we're going to see high IE usage in some markets well past that point. Just as an example, almost every Korean website that keep any sensitive data (and many, many that don't), rely on old IE plugins that are never going to be supported by Edge. Although the gov't is now throwing money at developers to rid themselves of the outdated tech, it's going to be a long process.

Chrome JUST took over IE in market share in the last few months here. All other browsers are sub-5%.

IE 11 ships also with Win8.1 and Win10, so IE11 will be around until 2022 or 2025.

IE11 is the new IE6 and will be around a long time in enterprise. Thank you Microsoft. It's epecially annoying as Edge is based just on a refactored and improved trident engine after all, so basically IE12 html engine under hood (and was already called "Edge" in DevTools in IE11).