I can not tell you how stable your current configuration is in contrast to EJB3 as I have never used EJB2.0 (too much to code ;-)!)
But in our company we have already finished two applications based on EJB3 including persitence and many other suff.
From my point of view the software (which runs on jboss) is absolutely stable and you can really rely on the platform!
We will go on with another two applications that use EJB3. I can only advice to investigate EJB3 features. After doing that you will find out that it really helps you to implement powerful and stable applications very easily.