This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Message driven beans are a way to integrate a JMS provider into your J2EE application. You could say that MDB is a replacement for JMS client code in J2EE applications, but JMS (or some vendor-specific API) is still needed for putting messages into the MOM system.