update-notifier-kde is installed by default in Kubuntu. It is on the livecd and is a recommends of the kubuntu-desktop package, so it will be installed by default if you install kubuntu-desktop from a gnome system.
update-notifier-kde is installed by default in Kubuntu. It is on the livecd and is a recommends of the kubuntu-desktop package, so it will be installed by default if you install kubuntu-desktop from a gnome system.