If you're using the JBoss application server to deploy your EJBs, JBoss has, since 3.2 version, interceptor technology that is very "aspect-oriented".
JBoss-AOP can also be used with EJBs within JBOss or any other application server. If you are running outside of JBoss you have to do precompilation and set the appropriate System property variables to point to the JBoss AOP XMl config files. See the tutorial/WIKI for more details. Get back to me here if you're still having trouble.