To answer my own question: The 'liveimg' instruction in the kickstart file causes
it to ignore any extra repos or packages that may be listed later. The workaround is to
either create a new live image to install from, or manually create the repo files and
install the packages in the %post section.
The documentation above is not very clear about this. It reads "The %packages
section is not required for oVirt Node. ", whereas the following is a little more
clear about the restriction:
"The %packages section is ignored when using the liveimg option."
--Mike