https://access.redhat.com/support/policy/updates/errata/
This will be of interest to pretty much everyone on the list.
"Red Hat offers support throughout four life-cycle phases—called Production 1, 2, and 3, and an Extended Life Phase—for each major release of Red Hat Enterprise Linux. With Red Hat Enterprise Linux 5 and Red Hat Enterprise Linux 6, Red Hat offers 10 years of Production Phase support from the initial product release date or general availability"