Make it easier to expose arbitrary objects as data service entities
1. Allow configuring the key property without having to use DataServiceKeyAttribute
2. Add a more general configuration API to wrap the data objects for publication as a data service entity, whatever the data objects structure may be
Phil Jones commented
Sometimes, it's not possible to follow conventions because the object being exposed can not be changed, and also adding the DataServiceKey attribute is not an option.
Here's a related question on StackOverflow: http://stackoverflow.com/questions/4626642/wcf-dataservice-how-do-i-avoid-dataservicekey-in-pocos