FC2 has been no longer supported for a while. That means that no package updates are released for it.
While that is true for the distribution release and upgrades from RH/Fedora, there is still support for FC2: google for "Fedora Legacy". DAG (apt.sw.be) (still) builds FC2 rpms as well for stuff like Snort.
Looking at the problems posted on LQ about FC4 I would never recommend upgrading to a bleeding edge release unless people are definately willing to bleed all over the place for the benefit of having "pretty much the newest versions of software".
My other option is CentOS 3, but their package seems to be even older, eventhough 3.6 was release recently.
CentoS gets its packages from RedHat, RH doesn't increase version numbers like others do. Check the info on the latest package release number, it usually has the fixes and patches.