Yes, probably we could in some way.
Googling we found this link, maybe a bit old but we would like to give it a chance anyway:
http://javabeans.asia/2008/05/16/jboss_clustering_shared_state_across_cluster_partition.html
So now we're thinking about having our "cache" in a hasingleton, every ejb pointing to it, and when a node goes down, the shared state will grant that no data is lost.
What do you think?
Thanks
Ale