If you are using a released version of Kubernetes, you should refer to the docs that go with that version.
The latest release of this document can be found [here](http://releases.k8s.io/release-1.4/docs/roadmap.md).Documentation for other releases can be found at releases.k8s.io.
Please watch the [Github milestones] (https://github.com/kubernetes/kubernetes/milestones) for our future plans.