* StatefulSet: The deprecated `pod.alpha.kubernetes.io/initialized` annotation for interrupting the StatefulSet Pod management is now ignored. StatefulSets with this annotation set to `true` or with no value will behave just as they did in previous versions. Dormant StatefulSets with the annotation set to `false` will become active after upgrading.

### **Application Deployment**
#### StatefulSet
* [beta] StatefulSet supports [RollingUpdate](https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/#rolling-updates) and [OnDelete](https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/#on-delete) update strategies.

### StatefulSet

- StatefulSets should always count `.status.availableReplicas` at the correct time without a delay. This results in faster progress of StatefulSet rollout. ([#136097](https://github.com/kubernetes/kubernetes/pull/136097), [@atiratree](https://github.com/atiratree)) [SIG Apps]

### Other (Cleanup or Flake)

- Validation now requires new StatefulSets with a `.spec.serviceName` field value to pass DNS1123 validation. Previously created StatefulSets with an invalid `.spec.serviceName` field value could not create any pods, and should be deleted.

- Avoid creating new controller revisions for statefulsets when cache is stale ([#67039](https://github.com/kubernetes/kubernetes/pull/67039), [@mortent](https://github.com/mortent))
- Fixes issue when updating a DaemonSet causes a hash collision. ([#66476](https://github.com/kubernetes/kubernetes/pull/66476), [@mortent](https://github.com/mortent))

- Improved parsing of label selectors ([#102188](https://github.com/kubernetes/kubernetes/pull/102188), [@alculquicondor](https://github.com/alculquicondor)) [SIG API Machinery]
- Introduce `minReadySeconds` api to the `StatefulSets`. ([#100842](https://github.com/kubernetes/kubernetes/pull/100842), [@ravisantoshgudimetla](https://github.com/ravisantoshgudimetla))

- Added readiness gates in extended output for pods ([#70775](https://github.com/kubernetes/kubernetes/pull/70775), [@freehan](https://github.com/freehan))
- Added `Ready` column and improve human-readable output of Deployments and StatefulSets ([#70466](https://github.com/kubernetes/kubernetes/pull/70466), [@Pingan2017](https://github.com/Pingan2017))

- Fix nil pointer dereference in azure cloud provider ([#85975](https://github.com/kubernetes/kubernetes/pull/85975), [@ldx](https://github.com/ldx)) [SIG Cloud Provider]
- Fix regression in statefulset conversion which prevents applying a statefulset multiple times. ([#87706](https://github.com/kubernetes/kubernetes/pull/87706), [@liggitt](https://github.com/liggitt)) [SIG Apps and Testing]

- `kubectl rollout restart` now works for DaemonSets and StatefulSets. ([#77423](https://github.com/kubernetes/kubernetes/pull/77423), [@apelisse](https://github.com/apelisse))