This file can can then be used to automatically enumerate methods + parameters, and provide nice C# stubs to send requests or fuzz payloads (and that is just a warm up on what you can do with it).
O2 has support for WSDL creation via this script: http://code.google.com/p/
To see it in action here is a example of how to consume it using O2's C# Scripting Environment http://www.o2platform.com/