While most on this list, myself included, might find that JBoss AOP is definately a production ready API. However, I find myself needing to explain why I find JBoss AOP more production ready that say AspectWerkz or AspectJ. While I may be foggy on the complete details and I'm excluding EJB 3 for teh sake of argument, but it is my understading that JBoss AS 4 make use of JBoss AOP for a number of internal services. So if you are running JBoss AS 4 but are somewhat timid about using aspects in your application for fear that JBoss AOP is immature, the app server you're using depends on the AOP framework already. Is that a true statement, or have I muddled the JBoss EJB3 implementation in with JBoss AS?
As for AspectWerkz, I'm well aware of the fact that 2.0 is the last version and it has been merged into AspectJ 5. Also, I have yet to see any major project or product claim to make use of AspectWerkz. AspectJ 5, well it's still in Milestone releases so that's not a tough argument.