* **[stable]** Add support to use NFSv3, NFSv4, and GlusterFS on GCE/GKE GCI image based clusters.
* **[beta]** Added support for mount options in persistent volumes.
* **[alpha]** All in one volume proposal - a new volume driver capable of projecting secrets, configmaps, and downward API items into the same directory.

## Deprecations

* Protobuf serialization does not distinguish between `[]` and `null`.
API fields previously capable of storing and returning either `[]` and `null` via JSON API requests (for example, the Endpoints `subsets` field)

* Filter published OpenAPI schema by making nullable, required fields non-required in order to avoid kubectl to wrongly reject null values. ([#85733](https://github.com/kubernetes/kubernetes/pull/85733), [@sttts](https://github.com/sttts))

Although clusters are enabled to support dual-stack networking, Pods and Services continue to default to single-stack.
To use dual-stack networking: Kubernetes nodes have routable IPv4/IPv6 network interfaces, a dual-stack capable CNI network plugin is used, Pods are configured to be dual-stack and Services have their `.spec.ipFamilyPolicy` field set to either `PreferDualStack` or `RequireDualStack`.

### HorizontalPodAutoscaler v2 graduates to GA

### EndpointSlices are now enabled by default

EndpointSlices are an exciting new API that provides a scalable and extensible alternative to the Endpoints API. EndpointSlices track IP addresses, ports, readiness, and topology information for Pods backing a Service.