I know I should have said this earlier, but I'm a bit concerned that WS-Eventing is requiring the presence of a header which is optional in the WS-Addressing specification that defines that header:
This OPTIONAL element (whose content is of type xs:anyURI) provides the value for the [destination] property. If this element is NOT present then the value of the [destination] property is "http://www.w3.org/2005/08/addressing/anonymous".
I foresee implementation problems due to the fact that the presence or absence of the wsa:To header may be solely under the control of the WS-Addressing message handler and may not be controllable by the code that creates the wse:Subscribe message.

- gp

Chou, Wu (Wu) wrote:
Many thanks for your comments and suggestions, especially the one regarding the cardinality. Here is an updated Infoset draft (v7) of the Subscribe Section of Eventing (clean+marked copies). We really moved a long way with all comments and contributions received.
- Wu Chou.