Very well put. From what I see this is like moving hysterix from the sidecar level to the network level. No need for applications to care of even know about leveraging the circuit-breaking. Very excited to try it out!
I'm curious if circuit breaking is better at the method level of the code ala Hystrix or at the network level. We need more in-the-wild experience reports I think...
The thing you can do at the code level is integrate it with your exceptions and protect against software integration bugs. Imagine that your RPC against a new version of a service fails because of bad data. With a library level circuit breaker, you can catch the failed exception and blacklist the new version of the service. With the network level, your resolution of failure detection is more limited.