I would not say EJB is a failure. I would say Entity Beans may have been a failure. We cover JPA, which I think will have success because it takes into account
patterns used by TopLink, Hibernate, JDO, and others.
The book is on the persistence layer, so we do not focus
alot on EJB 3. We discuss how using JPA in a managed environment like EJB 3 can make things easier in some scenarios, by allowing automatic propagation of the Persistence Context. I know other frameworks like Spring can give you similar advantages. But in general, I feel EJB 3 is a good thing.