There's one thing that needs to be corrected. The "headers" attribute no longer exists on the method elements. The example should be updated to demonstrate <header> sub-elements instead. It should also mention that the "name" is required but that either "value" or "expression" can be provided.
Also, we should at least briefly mention the ability to configure meta-annotations as an alternative to using @Publisher directly. There are some example in the tests here: PublisherAnnotationAdvisorTests (be sure to mention that the "channel" can be defined on the meta-annotation in those cases).