Yes, using clustering you can load-balance your calls at the home-interface level and, for SLSB, at the remote-interface level.
If you do not have any specific state-management problem regarding clustering, you can also simply use any hardware load-balancers in front of your cluster of jboss servers.
but is it possible with JBoss 2.4 ?, because i think it is just in alpha state with version 3.0....
Yes and no ;)
For the clustering features, you have to use 3.0.
Nevertheless, depending of your architecture, you can cluster JBoss by other means. Bill Burke wrote an article on how he did that for a very successful project: