Norm, this question and many responses to it have been flooding the Fedora forums since Sunday the 8th. I was able to get things looking like they were back to normal when I did what User Cyberjet suggested (I'll quote below), and rebooted. It required only su-ing to root, backing up and changing the configuration file, /etc/dbus-1/system.d/org.freedesktop.PackageKit.conf, but be careful.
Thanks to all.
I editied my org.freedesktop.Packagekit.conf (see below)and all my packages are restore under System Administration add/remove Software. This worked for me.
<!DOCTYPE busconfig PUBLIC
"-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
<!-- This configuration file specifies the required security policies
for the PackageKit to work. -->
<!-- Only user root can own the PackageKit service -->
<!-- Allow anyone to call into the service - we'll reject callers using PolicyKit -->
<allow send_interface="org.freedesktop.PackageKit.Transac tion"/> [ added this line as opposed to editing the above line and adding .Transaction]
To be honest, I haven't proven to myself that everything is right now, but at least my sources are back and I was able to add/remove software after I rebooted, and I was able to do a bug-fix update immediately afterwards.