you can find some information about the various files that can exist a '.esb' archive here.
Quote from the wike page:
the deployment.xml is optional, but can be used for 2 reasons:
make this .esb archive depend on other archives/MBeans, to specify classloading order (this includes message queues).
make the deployment of this .esb archive scoped.
And, what about jbm-queue-service.xml? What role has this file?
This is queue definition for JBoss Messaging. This file configures the queues that are used by the service. The file deployment.xml then declares that this ESB deployment depends on those queue. This makes sure that the queues are deployed and available before the .esb archive is deployed.