* OpenAPI spec is now available in protobuf binary and gzip format (with ETag support) ([#45836](https://github.com/kubernetes/kubernetes/pull/45836), [@mbohlool](https://github.com/mbohlool))
* Added support to a hierarchy of kubectl plugins (a tree of plugins as children of other plugins). ([#45981](https://github.com/kubernetes/kubernetes/pull/45981), [@fabianofranz](https://github.com/fabianofranz))

      * Added support for a hierarchy of kubectl plugins (a tree of plugins as children of other plugins). ([#45981](https://github.com/kubernetes/kubernetes/pull/45981), [@fabianofranz](https://github.com/fabianofranz))

    scheduling on the node condition `type` `Ready` `status` being `True` for pods
    that need to run prior to the network being ready.
* **Enhance Kubelet QoS**:
  * Pods are placed under a new cgroup hierarchy by default. This feature requires
    draining and restarting the node as part of upgrades. To opt-out set
    `--cgroups-per-qos=false`.
  * If `kube-reserved` and/or `system-reserved` are specified, node allocatable

  - [alpha] Kubelet launches container in a per pod cgroup hierarchy based on quality of service tier ([kubernetes/features#126](https://github.com/kubernetes/enhancements/issues/126))