Event Delivery Network allows publish-subscribe type of loose coupling between SCA components. This is similar to JMS/AQ model except that user is spared from remembering and using low level JMS connectivity details. Instead, SOA framework neatly abstracts these details in the Even Delivery Network so that users can purely focus on publishing and subscribing to events.
This approach is highly useful when an event publisher doesn’t know about the number or type of potential subscribers beforehand. Events can be published/subscribed from both BPEL as well as Mediator components.