Tomcat now allows session to be stored in memcached, couchbase etc also. I am not sure if Jboss provides some hooks to do this. It would be a good feature IMHO.
i would be interested in this type of solution. I find it a bit overkill to have to setup a jboss with infinispan to solve this problem. Furthermore if all the servers go down in the cluster does infinispan persist the SessionScoped information in memory?