TL;DR: Packages are now available, untested, for 3.0.19 on Fedora 17 and RHEL 6. Fedora 18 and RHEL 5 will have to wait until I am on a more stable network connection again.
Fedora Core 17 posed a serious challenge to the packaging of Passenger. One that, frankly, I had neither the time nor the energy to undertake. I toyed with it a few times in the vain hope of a quick solution, but one never came.
This past week I have been on vacation and I decided to dive back in with FC17 & 3.0.19. On Tuesday FC18 was announced, crystalizing exactly how far behind I've gotten.
I have had some good succes with FC17 & RHEL6. I can't download FC18 DVDs on this Mexican resort network. The RHEL5 build is also behaving badly, but may yet be due to this flakey network. Both of those will have to wait for me to return.
In the future I should be much more timely with the updates.