WSIF - Incorporating new bindings into client code is hard
As is explained in Web services are not just SOAP services, if you want to make an application that uses a custom protocol work as a Web service, you can add extensibility elements to WSDL to define the new bindings. But in practice, achieving this capability is hard. For example you have to design the client APIs to use this protocol. If your application uses just the abstract interface of the Web service, you have to write tools to generate the stubs that enable an abstraction layer. These tasks can take a lot of time and effort. What you need is a service invocation mechanism that allows you to update existing bindings, and to add new bindings.
See AlsoGoals of WSIF
WSIF - Web services are more than just SOAP services
WSIF - Tying client code to a particular protocol implementation is restricting
WSIF - Multiple bindings can be used in flexible ways
WSIF - Enabling a freer Web services environment promotes intermediaries