It's a little hard for me to understand what if anything this presents. At first I thought perhaps Protocol Buffers didn't have an RPC layer, and that this was bringing Protocol Buffers up to a comparable level of competitors like Thrift. Checking the Protocol Buffers docs though, I see they do already have services.

Is this simply a consistent, cross-language looking interface for authoring/consuming Protocol Buffers services? What makes this different from other Protocol Buffer implementations?