Red Hat has extended the life cycle of their Red Hat Enterprise Linux (RHEL) product line from seven to ten years beginning with RHEL5 which was initially released in March 2007 March. With Extended Life Cycle Support (ELS), this now means up to 13 years of support for RHEL5 or later. Thus RHEL5 will be supported until 2017 with standard support, 2020 if you purchase ELS.
Phase I support is now extended to 5.5 years. This is a change from the current 4 years for Phase 1 (It was increased from three years in mid 2008). During this period, Red Hat will take Requests for Enhancement (RFE) and other changes to the product. Thus RHEL5 Phase I will be extended until winter 2012 under this new life cycle.
While this represents a lot of sustaining engineering, it means Red Hat support is now unmatched within the Linux community and probably even for non-Linux platforms. This should drive a lot more sales of Red Hat Enterprise Linux.
Smart move, Red Hat!