How to improve WCF client proxy based on CreateChannel (not generated from WSDL) in C#
Instead of wrapping the proxy creation in a concrete service proxy implementation, I'd write a concrete service factory instead which in turn uses the ChannelFactory. The service factory class could also use an interface for creation, so you can have multiple concrete factories.

http://en.wikipedia.org/wiki/Factory_pattern

That way your code can continue to depend on the interface only, and you can change the way the proxy is created without writing concrete proxies. You could also have a "local service factory" which doesn't go over the wire.

Usage would be something like this instead:

var service = ServiceFactory.Create("http://127.0.0.1/svc");
var result = service.DoSomething(request);
// if you need cleanup..
ServiceFactory.Release(service);