We often get questions related to EJB and CDI, to the convergence (or divergence!) between those 2 important Java EE technologies. That particular topic was discussed a few months ago by Linda De Michiel (Java EE Specification Lead and former JPA Specification Lead) during JavaDay Tokyo 2015.
In her session, Linda first set the stage by discussing the history of both EJB and CDI, and how those 2 technologies have evolved over time. She then discussed the advantages and disadvantages, some of the gaps between those 2 technologies. Linda finally concluded by discussing some strategies to improve things going forward. For example, the @Transactional interceptors was introduced in Java EE 7. In Java EE 8, the idea is to continue on the path of extracting additional container services to make those more widely and more easily available in the platform. Java EE 8's CDI Security Interceptors and the new 'flexible MDB' comes to mind.