Between Fedora 12 and 13

Indeed. A predictable release cycle of 18-24 months was one of Red Hat's major selling
points for RHEL. And the RHEL5 General Overview document still claims 18-24 months,
even as they cavalierly violate that stated policy.

http://www.redhat.com/f/pdf/rhel/rhel5_overview.pdf

I used to use some CentOS for XDMCP servers. And on a release cycle of 18-24 months, that
works out OK. Though I tend to prefer to update at 12 month intervals. And they were doing
pretty well until now. Oh, RHEL5 was a bit late. But not enought to worry about. But I'm
really surprised that Red Hat is being as cavalier as they are in violating their stated policy.

Now that all my CentOS installations are purely servers, of the conventional sort, I don't
mind it that much. But it really is a bit of an issue for people who chose RHEL/CentOS for
desktop related work. Granted they've updated some of the desktop apps. But those are
apps that an admin would have been able to update fairly easily anyway. (And in fact, I
used to do a Firefox/Thunderbird/OO.o facelift toward the end of the release cycle, anyway.)
But it looks like RHEL/CentOS desktop folks are likely to be stuck with creaky old Gnome
2.6.16 and kernel 2.6.18 for some time to come, even if RHEL 6 is based upon F12.

Lest this post seem too negative (as some here seem to have developed a hair trigger
when I criticize things in the RH world) I will say that to their credit, the 7 year support cycle
for both server and desktop pretty much blows all competing distros out of the water. Even
Ubuntu's 3yr desktop/5 yr server support cycle for LTS releases does not match that. So
good on Red Hat for that. Presumably, that is a promise that they will not choose to break.
At least, I would be very surprised if they did.