Are the grpc examples intended to speak across languages?

Are the gRPC examples intended to interoperate? I can run the Java client-server examples entirely with Java. I can Go examples entirely with Go. But Go's hello world client won't talk with Java's hello world server.

In one terminal, from grpc-java:

$ ./gradlew :grpc-examples:helloWorldServer
:grpc-core:compileJava UP-TO-DATE
...
:grpc-examples:helloWorldServer
Mar 10, 2015 7:01:50 PM io.grpc.examples.helloworld.HelloWorldServer start
INFO: Server started, listening on 50051
> Building 96% > :grpc-examples:helloWorldServer

In another terminal, from grpc-common/go

$ go run greeter_client/main.go
2015/03/10 19:02:47 could not greet: rpc error: code = 12 desc = "Method not found: /helloworld.Greeter/SayHello"
exit status 1

Not the cross-language example I was expecting. SayHello is there, but is the problem with path or case sensitivity? Am I missing something, or is this cross-language cooperation an intent not yet realized?

(Caveat--I don't know Go, and I've been unable to build grpc for C++).