Arch Linux

Systemd will only be used if the system is started with systemd and even then upower will still invoke pm-powersave for power management.

Looking at all the bugs we have open about pm-utils, about what it fucks up, about what stupid default config it has and looking at how unmaintained this stuff actually is, I wouldn't even care about calls to pm-powersave.
As for "only used if system is started with systemd": some day that will be the only supported. With the release of GNOME 3.6 we will already build polkit without ConsoleKit support, which basically forces desktop users to run systemd.

That's the point of making it optional, at least systems started with systemd (which is now the officially preferd form) should be able to get rid of pm-utils.
As jan noted, pm-utils is not the best piece of software around.

It's not that I want to stick with pm-utils, but which piece of software should be responsible for power management then? Do the other distributions have anything that magically works better?

Matthias: There is nothing wrong with still keeping pm-utils for power management uses. There are alternatives however. There's laptop-mode-tools (which is way overkill/confusing IMO), and there are various other solutions using scripts. Currently my favorite solution is very simple: a single udev rule that calls a custom powersave script that I found on the forums a little while back: https://bbs.archlinux.org/viewtopic.php?id=148210. You know exactly what the script is doing and very easy to tailor to your system, for example here's the simple version I use on my system: http://pastie.org/4752076. There is also powerdown in the aur for a more 'complete' example.

Anyway, I definitely support pm-utils becoming an optional dependency is possible, unfortunately in my testing it seems even the new upower still uses pm-utils for some things. If I pacman -Rdd pm-utils, suspending by calling upower does not work (and in addition all suspend/hibernate options disappear in gnome), but doing it via systemctl suspend works fine. I've verified that new upower is using systemd for suspend on my system too (If I suspend via upower it shows in my systemd-suspend.service log). My theory is that upower still utilizes the pm-is-supported function to check if the system supports suspend (with pm-utils removed the error I get when attempting to suspend via upower is that the kernel does not support it). It should probably not be made an optional dependency until suspending via upower actually works without having pm-utils.

Hopefully in the future UPower will not need pm-utils at all anymore, I'd love to get rid of it since it looks like there hasn't been active development for at least 2 years. Unfortunately I use gnome, which needs upower, which seems to still need pm-utils, so in the meantime I've set RunPowersaveCommand=false in my UPower.conf and masked all the pm-utils powersave scripts.

Edited: Sorry, didn't test well enough. bwat47's statement is still correct, upower doesn't think it can suspend without checking with pm-utils even though it can.

Until upstream upower drops pm-utils-related functionality, you could try this:

https://aur.archlinux.org/packages/upower-git-systemd/

With upower-0.9.20, pm-utils-related functionality is disabled by default, unless you specify --enable-deprecated in ./configure, which is probably the case with the Arch Linux package right now. Why this?