One of the main reasons Enterprise JavaBeans (EJB) has been shunned in recent years is because EJB components can't be easily unit tested. Fortunately, the EJB 3.0 spec greatly changes the programming model and promises to make EJB—primarily entities—usable and testable outside the container. Oracle Application Server EJB 3.0 Preview makes testing of EJBs a reality. It offers you freedom to use Test Framework of your choice and does not require you to use any specific IDE.
Read my article how this is possible with Oracle's Entity Test Harness.