Wise decision! HF
EJB covers only EJB2 where as the current exam is for EJB3 which is totally different! I don't think any head first book for EJB 3 is coming soon!
Try
EJB3 in Action or
Enterprise Java Beans from OReilly which are really good!! Please check the SCBCD links for more info!
SCJP6, SCWCD5, OCP-JBCD5, OCE-JWSD6 OCE-JPAD6 , OCM-JEA5 1,OCM-JEA5 2,3,OCJP8 - Brainbench certifications: J2EE, Java2, Java2-NonGUI, JSP, SQL2000 Admin, SQL2000 Programming , Brainbench certified Java Programmer, Computer Programmer, Web Developer, Database Administrator