Description of problem:
I think the systemd preset fix applied so far to lightdm
needs tweaking since lightdm is not starting at boot.

Version-Release number of selected component (if applicable):
lightdm-1.3.3-2.fc18

* Tue Sep 04 2012 Rex Dieter <rdieter@fedoraproject.org> 1.3.3-2
- lightdm.service: After=+livesys-late.service (#853985)

How reproducible:
100%

Steps to Reproduce:
1. do a basic-x-windows (or xfce-desktop?) net install (or from dvd?)
2. boot and yum install lightdm-gtk if not already installed
3. reboot
  
Actual results:
lightdm does not start at boot

Expected results:
lightdm to start at boot-time.

Additional info:
According to Lennart, DM should not order their preset relative to livesys-late.service, since I assume that only works for Live (installs?)?