NOTE: This proposal was mainly written 2 years ago, many examples may already outdated, but the whole idea should still apply.
I have a dream, that the new JS APIs could be developed like good open source libraries, have reference implementation maintained by champions and volunteers in the whole lifecycle from stage 1 to stage 4, clearly marked as "experimental feature" not "polyfill", follow semver, and available in all platforms (all engines, browsers and node.js) automatically, accept issues and PRs in official github repo, can have branches to test new ideas, allow forks and healthy competition...