WS-RM isn't baked yet , generally.
There is also WS-AtomicTransaction, but it isn't generally available yet
either.

But, You can build the handshake protocol at the application layer.

When the client sends the request, the service can create a new UUID, and
store it in the database, along with a status code for the related
operation. The server can respond to the client with the UUID and the other
query response.  At some later point the client can ack the receipt of the
query result, and pass in the same UUID.  The server can then update the db
status code associated to that UUID (conversation ID).

or something similar.

-D