Comment 49 for bug 353278

I don't know - all previous upgrades I've just done what aptitude/the updater recommended.

OK, I looked at:

skroon@mania:~$ sudo aptitude show kpackagekit
Package: kpackagekit
New: yes
State: installed
Automatically installed: no
Version: 0.4-0ubuntu8.1
Priority: extra
Section: libs
Maintainer: Kubuntu Developers <email address hidden>
Uncompressed Size: 774k
Depends: kdebase-runtime (>= 4:4.2.1), kdelibs5 (>= 4:4.2.1), libc6 (>= 2.1.3), libgcc1 (>= 1:4.1.1), libpackagekit-qt11, libqt4-dbus (>= 4.5.0~+rc1), libqt4-network
         (>= 4.5.0~+rc1), libqt4-svg (>= 4.5.0~+rc1), libqt4-xml (>= 4.5.0~+rc1), libqtcore4 (>= 4.5.0~+rc1), libqtgui4 (>= 4.5.0~+rc1), libstdc++6 (>= 4.1.1),
         policykit-kde | policykit-gnome, software-properties-kde, packagekit (>= 0.3.14-0ubuntu3)
Description: KDE package management tool using PackageKit
 PackageKit allows to perform simple software management tasks over a DBus interface e.g. refreshing the cache, updating, installing and removing software packages
 or searching for multimedia codecs and file handlers.

 This package provides a package manager and a update notifier.
Homepage: http://www.packagekit.org

This indicates a dependency on policykit-kde OR policykit-gnome. And apparently I do have policykit-gnome installed (it's marked for Automatic installation):

skroon@mania:~$ sudo aptitude show policykit-gnome
Package: policykit-gnome
State: installed
Automatically installed: yes
Version: 0.9-1ubuntu3
Priority: optional
Section: gnome
Maintainer: Ubuntu Core Developers <email address hidden>
Uncompressed Size: 643k
Depends: libc6 (>= 2.4), libdbus-1-3 (>= 1.0.2), libdbus-glib-1-2 (>= 0.71), libgconf2-4 (>= 2.13.5), libglib2.0-0 (>= 2.18.0), libgnomevfs2-0 (>= 1:2.17.90),
         libgtk2.0-0 (>= 2.15.0), libpolkit-dbus2 (>= 0.7), libpolkit-gnome0 (>= 0.7), libpolkit-grant2 (>= 0.7), libpolkit2 (>= 0.8), libsexy2 (>= 0.1.8), policykit,
         dbus-x11
Description: GNOME dialogs for PolicyKit
 PolicyKit-gnome provides a D-Bus session bus service that is used to bring up authentication dialogs used for obtaining privileges.
Homepage: http://hal.freedesktop.org/docs/PolicyKit-gnome/

Tags: implemented-in::c, interface::x11, role::program, security::authentication, suite::gnome, uitoolkit::gtk