David:
Marty is saying that we need to at least require delivery channels to
have unique endpoint addresses for 1.1.
Using the ServiceBinding override mechanism, it is possible to
specify a delivery channel with syncReplyMode for a particular
action (for the receiver).
From the CPA, both the sender and the receiver should know that the
action in question is associated with a unique delivery channel. When a
message arrives on the associated endpoint address, the receiver
should have no difficulty to know that it has to respond synchronously
because the delivery channel is a synchronous one.
-Arvola