Of course I'm quite biased here, but at least let me say it's quite unfair comparing the webservice stack you had in JBoss 4.0.2 many years ago (which I think was not even called jbossws) with the recent Axis2. Btw, the webservice stack of JBoss is not based anymore on Axis since *years*.
My suggestion would be to evaluate a recent version of JBossWS (3.2.x), pick the stack flavour you prefer (JBossWS-Native, JBossWS-CXF or JBossWS-Metro) according to your needs. Also keep in mind that moving to a recent AS version (we're currently working on JBoss AS 6.0.0.M3...) is more that suggested, you're likely to suffer from performance issues, bugs, etc. staying with an AS that is *many years* old.
Regarding the usual need for keeping the same wsdl contract while upgrading the software, consider a contract first development using wsconsume tool (even if I fear you were using rpc/encoded style at that time... and almost no ws stack support that nowadays)