Recently I wanted to use the "extract class from parameters" to refactor simplify methods of current WCF (Windows Communication Framework) interfaces. As you may know WCF requires contracts to be serializable, which means that the properties for the parameter generated by the "extract class from parameters" feature needs to be updatable. I would like to sugget that the feature has a "readonly" checkbox, which is checked by default. When checked, the behaviour will be exactly as it is now (all properties are readonly). If not checked, properties generated will be updatable. This will save me from having to remove the readonly flag from each private field and adding additional "set" methods for properties. For some classes that could save me a lot of work!