What has changed in f18 is that GNOME components
(gnome-settings-daemon, gnome-shell) are now using logind, because
it offers features that we want (inhibitors and delay inhibitors).
upower has also been changed to use logind, and NetworkManager is
listening for PrepareForSleep.
NM should, but it does not yet:
https://bugzilla.redhat.com/show_bug.cgi?id=902332
And there are dozens of applications out there that used to utilize the UPower signal and
haven't been given proper chance to adjust to the "new approach", so they
are broken at the moment.
I don't have any objections to the new suspend framework, it sounds good, but
GNOME+systemd developers haven't ensured much continuity. Which is something I see a
lot in OSS world, and it doesn't have to be this way. If GNOME developers had ensured
the old signals had been sent even with the new suspend framework, at least for one
release, we wouldn't have had so many broken applications.