The OSG has published a new policy for supporting software releases:
https://twiki.opensciencegrid.org/bin/view/SoftwareTeam/ReleaseSeriesSupportPolicy
Following this policy, OSG is announcing that support for the OSG 3.1 release series will end on April 30, 2015. Until then, OSG will backport critical bug and security fixes to OSG 3.1. Please migrate existing installations to OSG 3.2 prior to this date. Early plans are forming for OSG 3.3, but no release date has been set and OSG 3.2 will likely be the only supported release series for a while after April, 2015.
If you have any concerns or questions about this date please contact OSG Operations and Software by creating a ticket at http://ticket.grid.iu.edu/submit.