Today, the first version of polkit-qt-1 and polkit-kde-1 have been released to the public. Thanks to these tools, KDE applications now integrate nicely with the new polkit-1 with a native authentication dialog. An authorization manager, the equivalent of the Polkit Authorization System Settings module, will be included in future releases.
I recently upgraded a minimal installation of Ubuntu (with no full-fledged DE) from precise to saucy and since doing so I'm no longer able to mount removable drives as a normal user. I googled a bit and found it's something related to policykit... but I can't find any example of how to invoke policykit in an .xinitrc file, i.e., without using a display manager.