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.
Stateful or stateless is just EJB configuration option. Underlying bean still implements same "javax.ejb.SessionBean" interface. For bean implementing this interface, remove() method is optional and so is annotation.