Sage has a fairly advanced packaging for Debian/Ubuntu [thanks to all the hard work by Tim Abbott], but we are not 100% done yet. For details see
Some work had been done for PCLinuxOS [which is rpm based and a FC derivative IIRC], but that work has mostly consisted of not building the already available packages in their repo. For Debian about 25 new packages had to be created, so I expect a little more work for a RHEL derived distro. Some people using Fedora have expressed interest - see
but not much seems to have happened there so far. We would certainly welcome rpm base packaging of Sage and its components, but so far few people from the Sage community itself have gone down that way. But since there are several rpm based distros interested it certainly looks like their efforts can be combined to lessen the burden on each individual camp.
Building a monolothic Sage rpm is possible with little effort [I have done so], so you would need to tell us how you would like to proceed from here. Besides Sage itself there are many interesting components that people using Scientific Linux might be interested in.