Update roadmap

To reflect decisions agreed in meetings

ROADMAP.md

@@ -1,18 +1,53 @@
 # ROADMAP
 
-# 1.9
+The kops 1.N.x version officially supports kubernetes 1.N.x and earlier.  While kubernetes 1.99 will likely run with kops 1.98,
+the configuration will probably not be correct (for example docker versions, CNI versions etc).
 
-## Must-have features
+kops 1.N.0 is released when it is believed that kubernetes 1.N.x is stable, along with all the core addons (e.g. networking).
+This can mean that kops can release months after the release of kubernetes.  It's also not a deterministic release criteria,
+particularly with some networking plugins that are supported by kops but themselves still under development.  We discussed
+this challenge in kops office hours in March 2018, and the consensus was that we want to keep this, but that we should release
+alphas & betas much earlier so that users can try out new kubernetes versions on release day.
 
-* Support for k8s 1.9
+For the next few releases this means that:
+
+* 1.9.0 release target April 7th
+* 1.10 alpha.1 with release of kops 1.9.0 (April 7th)
+* 1.10 release target April 28th
+* 1.11 alpha.1 at release of kops 1.10
+* 1.11 beta.1 at release of k8s 1.11
+* 1.12 alpha.1 at release of kops 1.11 etc
 
-## Other features
 
-* Use NodeAuthorizer / bootstrap kubeconfigs  [#3551](https://github.com/kubernetes/kops/issues/3551)
+### _kops 1.10_
 
+* Support for kubernetes 1.10
+* Full support for GCE
+* Make the etcd-backup tool enabled-by-default, so everyone should have backups.
+* Allow users to opt-in to the full etcd-manager.
+* Make etcd3 the default for new clusters, now that we have an upgrade path.
+* Beginning of separation of addon functionality
+* Support for more clouds (Aliyun, DigitalOcean, OpenStack)
+
+### _kops 1.11_
+
+* Make the etcd-manager the default, deprecate the protokube-integrated approach
+* kops-server
+* Machines API support (including bare-metal)
 
 # HISTORICAL
 
+# 1.9
+
+## Must-have features
+
+* Support for k8s 1.9 _done_
+* etcd backup support _done_
+
+## Other features
+
+* Use NodeAuthorizer / bootstrap kubeconfigs [#3551](https://github.com/kubernetes/kops/issues/3551) _no progress; may be less important with machines API_
+
 # 1.8
 
 ## Must-have features