I am looking into merits of migrating our production system [OS: Linux] from Tomcat to the JBoss. We have a tomcat 5.0 running our highly multi-threaded application. And I don't see us using any EJBs anytime in the near future, just the servlet container. So is there any valid argument for migrating to JBoss.
JBoss uses Tomcat as its Web Server. JBoss also has a very pluggable architecture, so theoretically, you could cut most of the services out of JBoss except for Tomcat and a few other things, leaving you with pretty much what you have now.
The benefit you might see with this approach is the ability to plug some of those services back in later if you need them. If you are building on Tomcat and are finding yourselves writing custom services that are similar to what is available in JBoss, then you might consider this strategy.
If not, I would probably advise you to stick with Tomcat. That being said, I don't know much about your application/architecture, so its hard to judge.