I agree it is most of those "bad" things. But I don't see it as a long term approach (i.e. for JBoss 5.x). I see it as an easy way to layer factory/deployment functionality on top of the the 3.2 and possibly 4.0 codebase, until we have better support in the new kernel.
If we break the problem into pieces, we have the issue of creating a new "service" that will survive a server restart (service being possibly a collection of mbeans) What options do exist now that wouldn't distrupt the jboss deployment model, apart from creating one or more deployment descriptor and either move them to deploy or submit them directly to the main deployer?
I think I should just commit the prototype that does the basic template/based service creation into ./undeploy dir, moving back and forth to ./deploy and removing from undeploy (without any feedback on the fate of the deployment), so you could all have a look and we can talk more specifically about it.