*   The Kubelet's feature gates are now specified as a map when provided via a JSON or YAML KubeletConfiguration, rather than as a string of key-value pairs, making them less awkward for users. ([#53025](https://github.com/kubernete...

- OIDC authentication will now fail if the username asserted based on a CEL expression config is the empty string.  Previously the request would be authenticated with the username set to the empty string. ([#123568](https://github.com/kubernetes/kubernetes/pull/123568), [@enj](https://github.com/enj))

- Fixed CEL estimated cost of `replace()` to handle a zero length replacement string correctly.
  Previously this would cause the estimated cost to be higher than it should be. ([#120097](https://github.com/kubernetes/kubernetes/pull/120097), [@jpbetz](https://github.com/jpbetz)) [SIG API Machinery]

- The client label for apiserver_request_count and apiserver_request_total now no-opts and merely records an empty string. ([#87673](https://github.com/kubernetes/kubernetes/pull/87673), [@logicalhan](https://github.com/logicalhan)) [SIG API Machinery, Instrumentation and Scalability]

- The kube-controller-manager managed signers can now have distinct signing certificates and keys.  See the help about `--cluster-signing-[signer-name]-{cert,key}-file`.  `--cluster-signing-{cert,key}-file` is still the default. ([#90822](https://github.com/kubernetes/kubernetes/pull/90822), [@deads2k](https://github.com/deads2k)) [SIG API Machinery, Apps and Auth]

  
  The API does include a few breaking changes:
  - The "extraArgs" component construct is now a list of "name"/"value" pairs instead of a string/string map. This has been done to support duplicate args where needed.
  - The "JoinConfiguration.discovery.timeout" field has been replaced by "JoinConfiguration.timeouts.discovery".