Well, a web connector pool is in its nature a singleton shared ressource. Hence, there is no need to make it deployable. Datasources might be shared between applications too, but thats not the only case. As JMS resources - which as I understand are deployable for that reason - datasources are often used in "application scope" only. Therefore it makes perfect sense to provide (e.g. maintain) a way to deploy them along with your application - together with your JMS-Destinations and preferably cache configurations too.