TContract ServiceChannel
{
get { return serviceChannel as TContract; }
}

The actual code is bit more complicated as before we return the service channel we check if the channel is ready for invoking (check if it was already created, if it faulted, etc…). This actualy produces a more rubost solution than your because we only need to create one class (we have to write and maintain less code) and use it to all of our services and we can even add extra verifications before invoking the channel. Also we don’t have to change our client class every time we make a change in the Service Contract.
At the end you say: “ If you are running with .NET 3.5 you can even leave out the Data and Member Contract attributes of the data classes (same as choosing “Reuse types in referenced assemblies” when using thee Add Service Reference feature).”
I’m not sure what you meant with this but by default a class with an empty constructor and public get/set properties is a DataContract and all the properties with public getter and setter are considered as part of the contract (DataMember). Also this is not the as choosing reuse types in reference assemblies. All the types in a WCF contract have to be DataContract and whether or not you explicitly mark the classes with DataContract you can use this option.