This is much different than what we're seeing with the evolution of, say, JavaScript or PHP. There, the languages are pretty horrific to begin with. Any "improvements" tend to be yet another hack layered upon one or more earlier hacks. Even in the best cases, these "improvements" are merely bringing JavaScript and PHP to where many other languages were 10 or 20 years ago (if not going back much earlier).
I think the fact that Rust is already so coherent makes these improvements and refinements much more impressive. It's much harder, and requires more real innovation, to improve something that's already great to begin with. Yet that's exactly what we're seeing with Rust.
From dictionary.com:
1. in the literal or strict sense: What does the word mean literally? 2. in a literal manner; word for word: to translate literally. 3. actually; without exaggeration or inaccuracy: The city was literally destroyed. 4. in effect; in substance; very nearly; virtually.
Notice definition #4.
Harmony (ES6). Isn't it obvious?
>or revisions (jsnext, asmjs) that IE won't ever adopt.
Seeing that MS caught up in the Javascript JIT game, offer Node.js for Azure, and added HTML5 features, SVG, CSS transformations and even WebGL in the latest IE head why would you say they'll never adopt JsNext?
Heck, even them adopting asm.js is not much of a stretch.
1: https://github.com/mozilla/rust/wiki/Doc-detailed-release-no...