Hi Andrew,
Unfortunately we won't have MDB support in Final. We deproritized anything non-web profile once we found out that due to recent certification requirements, we have to do extra work to make sure that there is no way that a user can consume the feature in whatever our certified configuration (and distribution) is. It will be one of the first features we have in early 7.1 releases, however if there is enough demand we may be able to backport something in a 7.0.x update.
In the meantime you could use a traditional JMS listener inside of an ejb singleton deployment. Unless you would rather wait.