- Resolves regression generating informers for packages whose names contain `.` characters ([#82410](https://github.com/kubernetes/kubernetes/pull/82410), [@nikhita](https://github.com/nikhita))
- Resolves issue with `/readyz` and `/livez` not including etcd and kms health checks ([#82713](https://github.com/kubernetes/kubernetes/pull/82713), [@logicalhan](https://github.com/logicalhan))

- Kubernetes will try to acquire the iptables lock every 100 msec during 5 seconds instead of every second. This is especially useful for environments using kube-proxy in iptables mode with a high churn rate of services. ([#85771](https://github.com/kubernetes/kubernetes/pull/85771), [@aojea](https://github.com/aojea)) [SIG...

* Fixed a race condition in k8s.io/client-go/tools/cache.SharedInformer that could violate the sequential delivery guarantee and cause panics on shutdown. ([#59828](https://github.com/kubernetes/kubernetes/pull/59828), [@krousey](https://github.com/krousey))

- Introduce support for CEL optionals (see [CEL spec proposal 246](https://github.com/google/cel-spec/wiki/proposal-246)).
  This feature will not be fully enabled until a future Kubernetes release (likely to be v1.29), but is added in v1.28 to enable
  safe rollback on downgrade. ([#118339](https://github.com/kubernetes/kubernetes/pull/118339), [@jpbetz](https://github.com/jpbetz)) [SIG API Machinery, Auth, Cloud Provider and Testing]

    - [SIG VMWare](#sig-vmware-1)
    - [SIG Windows](#sig-windows-1)
  - [Other Notable Changes](#other-notable-changes-11)
    - [Bug Fixes](#bug-fixes)
    - [Not Very Notable (that is, non-user-facing)](#not-very-notable-that-is-non-user-facing)
  - [External Dependencies](#external-dependencies)
- [v1.12.0-rc.2](#v1120-rc2)
  - [Downloads for v1.12.0-rc.2](#downloads-for-v1120-rc2)

- EndpointSlice controller is now less likely to emit FailedToUpdateEndpointSlices events. ([#99345](https://github.com/kubernetes/kubernetes/pull/99345), [@robscott](https://github.com/robscott)) [SIG Apps and Network]

* Fixed a race condition in k8s.io/client-go/tools/cache.SharedInformer that could violate the sequential delivery guarantee and cause panics on shutdown in Kubernetes 1.8.* and 1.9.*. ([#59828](https://github.com/kubernetes/kubernetes/pull/59828), [@krousey](https://github.com/krousey))

* Bump Heapster to v1.5.2 ([#61396](https://github.com/kubernetes/kubernetes/pull/61396), [@kawych](https://github.com/kawych))
* Fixed a race condition in k8s.io/client-go/tools/cache.SharedInformer that could violate the sequential delivery guarantee and cause panics on shutdown. ([#59828](https://github.com/kubernetes/kubernetes/pull/59828), [@krousey](https://github.com/krousey))

- Fixed kubelet startup getting stuck with `NewVolumeManagerReconstruction` feature enabled and a...

* new dhcp-domain parameter to be used for figuring out the hostname of a node ([#61890](https://github.com/kubernetes/kubernetes/pull/61890), [@dims](https://github.com/dims))
* Disable ipamperf integration tests as part of every PR verification. ([#61863](https://github.com/kubernetes/kubernetes/pull/61863), [@satyasm](https://github.com/satyasm))