JBoss is an excellent open source J2EE application server. It would be really good if RedHat JBoss packages were available with Red Hat Linux, or packaged on the application CD (which might be more appropriate given that it requires J2SE). This would make developing and deploying web applications on Red Hat Linux simpler. I suppose JBoss _might_ be made to work with gcj/classpath (in the same way as tomcat has recently been made to work), in which case it would make an excellent addition to the core linux distribution.
Did you look at http://www.jpackage.org/ ?
We have packaged JOnAS from ObjectWeb as part of our Application Server offering. JBoss will not be packaged.