Add slide about cluster federation

docs/whatsnext.md

@@ -136,6 +136,44 @@ And *then* it is time to look at orchestration!
 
 ---
 
+## Cluster federation
+
+--
+
+![Star Trek Federation](startrek-federation.jpg)
+
+--
+
+Sorry Star Trek fans, this is not the federation you're looking for!
+
+--
+
+(If I add "Your cluster is in another federation" I might get a 3rd fandom wincing!)
+
+---
+
+## Cluster federation
+
+- Kubernetes master operation relies on etcd
+
+- etcd uses the Raft protocol
+
+- Raft recommends low latency between nodes
+
+- What if our cluster spreads multiple regions?
+
+--
+
+- Break it down in local clusters
+
+- Regroup them in a *cluster federation*
+
+- Synchronize resources across clusters
+
+- Discover resources across clusters
+
+---
+
 ## Developer experience
 
 *I've put this last, but it's pretty important!*