1. Within a computing system that includes a service implementation of a web service contract document, which defines how the service implementation is to communicate with a particular service, a method of automatically changing at least a portion of the service implementation in response to changes in the web service contract document, the method comprising: an act of receiving a web service implementation that has been constructed in accordance with a first web service contract document that describes how the web service implementation is to communicate with one or more services; an act of receiving a second web service contract document, which defines one or more changes to the first web service contract that affect the behavior of the web service implementation in such a way that the web service implementation cannot communicate with one or more endpoints that expect the second contract to be implemented; an act of identifying the one or more changes between the web service implementation and the second web service contract document; and based on the one or more changes identified, a step for automatically modifying at least a portion of the web service implementation to conform at least partially with the second web service contract document.