I create xsd's based upon client's documentation and all of the xsd's have attributes. I have been using xsd.exe to generate the classes from the xsd's, but I read that attributes aren't supported for the DataContractSerializer. Why not? Does this mean that I can only have an soap+xml file with just elements? This is not possible because I don't create the requests. Is there a way to specify to svcutil to recognize attributes?
DataContractSerializer was created with a "code-first" philosophy in mind - it maps well to most programming languages (records, lists), and it doesn't handle all of XML constructs (such as attributes, or out-of-order elements, for example) for performance reasons.
WCF (svcutil) still supports using the XmlSerializer, which can handle AFAIK all of the XML constructs. svcutil should create a contract using the XmlSerializer if the DataContractSerializer can't handle it.