There are times when its not possible to determine which version of 
soap to use and providing a WSDL is not optimal.  In particular:

1 - Sections 8 and12 of MEX show up to put policy in an EPR.
This allows a consumer of that EPR to know how to construct messages
to that endpoint - however, the one piece of critical information
needed is the soap version.  While it might be possible to include
WSDL in the EPR, the purpose of just putting the policy in there is
to avoid putting the complete WSDL in there. 

2 - Not all endpoints have WSDL.  For example, its possible to construct
a wse:NotifyTo endpoint that doesn't use WSDL at all. People are expected
to put Policy into the wse:NotifyTo so that sink knows how to send the
Notifications.  Using this mechanism it can know everything except the
soap version.

proposal:
define a new SOAP assertion either in MEX or as a separate spec.
See the attachment for what the spec might look like.  If we want it
as part of MEX the just pull section 3 into a new section of MEX.