you can remove polkit-nosystemd regardless of dependencies by using :
$ sudo pacman -Rdd polkit-nosystemd
Edit : i suspect that you have a trouble to install cups under xfce4, right?
So i do not think about this trouble. i need to make a corrections on polkit-nosystemd package to provide directly consolekit.
i make a soon as possible, sorry for this inconvenient
Anyway for the moment :
if you remove consolekit you can not use the reboot/restart/shutdown option on xfce4-panel. only logout work. you need to edit too ~/.xinitrc file and remove --with-ck-launch, so the line look like this :
exec startxfce4
Edit : i have made a rapid test on polkit-nosystemd package, seem to be good but i need time to provide it on the repo. it will be available tomorrow.