Futures-rs and Tokio were started by prolific Rust contributors so the community is gravitating towards making these crates the canonical async libraries for Ru

Futures-rs and Tokio were started by prolific Rust contributors so the community is gravitating towards making these crates the canonical async libraries for Rust. Since async primitives are so important and used in so many different ways, the maintainers are taking it slowly so that the community can provide as much feedback as possible. It may not be in the standard library but futures/Tokio will be the basis for most high level async in Rust so it's critical to get it right.