Kernel appears to be F18, though:
$ uname -a
Linux harrier.xxx.com 3.9.11-200.fc18.i686.PAE #1 SMP Mon Jul 22 21:19:06 UTC 2013 i686 i686 i386 GNU/Linux
By way of additional info, after running fedup with no errors, I rebooted, picking the "Fedora Upgrade" option. Then went to dinner. When I returned, the system was *powered completely down*. Booting it revealed the F18 message on the progress bar.
yum update shows a string of "some-package.fc19 is a duplicate of same-package.fc18
I don't see anything untoward in /var/log/fedup.log. Seems whatever has happened occurred after the reboot into the upgrade.