Ted Neward has a fantastic article over at ClrGeeks on StronglyTyped Infosets in .NET.

The solution he presents is a good compromised between the loosely-typed extensibleXML world and convenience of strongly typed objects.

As we move toward a Web Services world that allows to stay closer to the native XMLmessages, I think we're going to see data being shipped around in these sorts of objects.All we need now is a generative framework for building these classes from XSD schemas,and we're good to go.