I'd like to go with an RFC-based governance model (similar to Rust, Ember or Swift) that looks something like this: new features go through a public RFC that describes the motivation for the change, a detailed implementation description, a description on how to document or teach the change (for kpm, that would roughly be focused around how it affected the usual workflows), any drawbacks or alternatives, and any open questions that should be addressed before merging. the change is discussed until all of the relevant arguments have been debated and the arguments are starting to become repetitive (they "reach a steady state") the RFC goes into "final comment period", allowing people who weren't paying close attention to every proposal to have a chance to weigh in with new arguments. assuming no new arguments are presented, the RFC is merged by consensus of the core team and the feature is implemented. All changes, regardless of their source, go through this process, giving active community members who aren't on the core team an opportunity to participate directly in the future direction of the project. (both because of proposals they submit and ones from the core team that they contribute to)

The nice thing about leading with an RFC process is that it shows potential contributors, from the get-go, that they have a path to contributing even big ideas.

It's friendlier to contributors. Dart is substantially easier to learn than Ruby, and many Sass users in Google in particular are already familiar with it. More contributors translates to faster, more consistent development.