Awhile back, I asked for input on the DataView property and what API you would like to have for it. We were designing a new class that would be created expressly for the purpose of the DomainDataSource.DataView property. We wanted the API to do two thing for you: 1) Give you easy access to the properties and methods you will frequently use on the collection; and 2) Hide the properties and methods that are required to be implemented for interfaces but that you would not need to access programmatically often. The result of this effort was a class named DomainDataSourceView. You will see this with the PDC release of RIA Services.