As noted in the OP, there was some preliminary discussion at
http://lists.fedoraproject.org/pipermail/robotics/2011/000529.html but nothing ever came of it to my knowledge. There is indeed some interest to see ROS in Fedora's repositories, but nobody is spearheading the effort. If you'd like to continue the discussion on the robotics list we can try to coordinate and get things started there.