This week's book giveaway is in the OCAJP forum. We're giving away four copies of Programmer's Guide to Java SE 8 Oracle Certified Associate (OCA) and have Khalid A Mughal & Rolf W Rasmussen on-line! See this thread for details.
Are you talking about EJB 2 or 3? I still see some legacy applications using EJB 2, including IBM products like WebSphere Commerce. EJB 3 is seeing some adoption, but many of the applications I use just leverage JPA without EJB 3. I still recommend understanding the core concepts of EJBs as they are useful patterns. This includes understanding the difference between entity and session beans, transaction management, etc.