No, it would be an additional option. ZeroMQ will always be supported - we use it enormously at dotCloud. Another transport we plan on supporting is websocket.
Each transport has its advantages. Zmq is incredibly efficient, very flexible and leaves you in full control of your network topology, but it requires a firewalled trusted network, and doesn't provide ready-to-use broker or naming facilities.
Redis can be used as a very efficient broker and discovery component, and can be more easily included in your web stack, but it limits your flexibility and becomes a potential spof.
The good news is, once zerorpc supports multiple transports you can stary with one and swap it out for another without changing your code.
Each transport has its advantages. Zmq is incredibly efficient, very flexible and leaves you in full control of your network topology, but it requires a firewalled trusted network, and doesn't provide ready-to-use broker or naming facilities.
Redis can be used as a very efficient broker and discovery component, and can be more easily included in your web stack, but it limits your flexibility and becomes a potential spof.
The good news is, once zerorpc supports multiple transports you can stary with one and swap it out for another without changing your code.