>If a Winform running on the client end passes a dataset to a Web Service (which in turn passes it to the middle-tier), is the dataset XML when it gets to the Web Service, or do we have to do a serialization/deserialization along the way?
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My understanding is that it would be XML. The web service proxy class should handle all serialization for you. Open your project and click on the Project > Show all Files menu. Drill down into your Web service reference in Solution explorer and you will see the source code for the proxy class. That class will have all the serialization attributes setup for you.