As of this Weekend we are not using JBoss anymore. An issue with DataSources and XWiki pushed me over the edge and finally I had enough with the little things that are broken in JBoss.
And so I went back to my roots and gave Jetty another shoot. And behold I tested Jetty and switched the production server in less than 4 hours. There are still so kinks to be ironed out especially replacing AJP with Mod Proxy but that seems doable.
Have fun - Andy