http://lwn.net/Articles/592723/ "So the goal for CentOS is to create a next-generation platform that is supported for a longer period of time than Fedora is. Ten years would be good, but most people just want something longer than 13 months, he said, and *2–3 YEARS SEEMED TO BE A SWEET SPOT*." (emphasis added by me). Pertinent question: are SL users "most people" ?