The status of this "phase 1" effort for Shibboleth is that my pull request is now in, and I'm eager for feedback while this stuff is still fresh in my mind. :)
If you'd like to kick the tires on some pre-release code, I have set up a Jenkins job from which you can download a war file to deploy to a system OTHER THAN YOUR PRODUCTION SYSTEM. Please note that to run the war file, you must first upgrade to Dataverse 4.3 which contains some
database changes. As of this writing, the latest build (#2) can be downloaded by clicking "dataverse-4.3.war" at
https://build.hmdc.harvard.edu:8443/job/shibtest.dataverse.org-build-2939-shib/2/edu.harvard.iq$dataverse/