I respectfully must slightly disagree with you.
In terms of security fixes and new hardware drivers, the issues of
backporting (that is, to make a bit of software compatible -- buildable
-- with the core gcc/g++ environment of a "very old" Linux, including
SL) may require a great deal of
New distro releases imply:
1) security fixes,
2) bug fixes,
3) new hardware drivers,
4) new applications,
5) and changed behavior (ie, Gnome2 to Gnome3).
(the list is probably not complete)
How much work (staff hours per year, plus volunteer help)
would it take to do JUST (1) and (2) for