Maybe of interest to the readers of this thread; I wrote an article of my experiences with installing a JASPIC SAM programmatically at: http://arjan-tijms.blogspot.nl/2012/11/implementing-container-authentication.html
Related to this is the following Java EE spec issue: http://java.net/jira/browse/JAVAEE_SPEC-9
My personal stake here is that for the OmniFaces project (http://code.google.com/p/omnifaces) we were looking into creating a simplified authentication process that also better integrates with JSF. JASPIC seemed very viable to base this on, if it weren't for the issues with configuration, and among others the fact it's not active by default in JBoss AS/EAP (our showcase app runs on JBoss AS and EAP on OpenShift, so JBoss is obviously a very important target container for us).