Extending the functionality of an existing Web Service

In the Interface Description section of the charter there is the following:

 Developers are likely to want to extend the functionality of an existing 
 Web service.  The Working Group will look into extending interface descriptions
 in a decentralized fashion, i.e. without priori agreement with the original
 interface designers. 

We read this as WSDL 2.0 providing a mechanism for versioning a Web Service,  
at least an outline how to add contents of a message without breaking existing 
interactions.

There appears to be nothing in the requirements relating to how to version a
Web Service beyond being able to identify versions of services and descriptions.

Has this issue been lost, or is our reading of the charter incorrect ?

Paul

-- 
Paul Sumner Downey
Web Services Integration
BT Exact