[jboss-user] Upgrade advise: 4.0.5 vs 4.2.2 vs 5.0.0

[Achilleas Mantzios]

Hi,
we are about to upgrade to a new fresh hardware and we are considering upgrading to latest and greatest
jboss, postgresql as well.
Currently we are on 3.0.3 (for various reasons, mainly lack of time).
At some point back in 2006, i had come up with a plan for migration to (then) 4.0.4, and i had writen 
instructions how to deal with eclipse, packaging, EJB configuration, and the test succeeded.
However we were unable to upgrade due to lack of testing time, and lack of a paralel test system.
Now we have the hw, + i have to do the upgrade.
So the questions are
a) which version should i turn to?
b) What are the changes between 4.0.4->4.2.2->5.0.0
I know its been 2 years under development, but what are the caveats someone should be aware of?

Thank you for any directions.
-- 
Achilleas Mantzios