How to design and implement a simple WCF service relay?

Question

We are in the process of designing a simple service-oriented architecture using WCF as the implementation framework. There are a handful of services that a few applications

Answer 1

It seems it is sufficient to build an interface as follows:

[OperationContract(Action="*", ReplyAction="*")]
Message CallThis(Message msg);

I also found this post useful for implementing the CallThis method by "fiddling" with Message objects. A basic implementation of the CallThis method follows:

public Message CallThis(Message message) {
    MessageBuffer buffer = message.CreateBufferedCopy(524288);
    Message output = buffer.CreateMessage();
    output.Headers.To = ;

    BasicHttpBinding binding = new BasicHttpBinding();
    IChannelFactory factory = binding.BuildChannelFactory();
    factory.Open();

    IRequestChannel channel = factory.CreateChannel(new EndpointAddress());
    channel.Open();

    Message result = channel.Request(output);

    message.Close();
    output.Close();
    factory.Close();
    channel.Close();

    return result;
}

Adding authentication and authorization should be quite straightforward.