Hi All,
With some help from others and piecing together a lot of incomplete documentation, I finally figured out how to get autologin to work with Xfce Fedora Core 21.
/etc/lightdm/lightdm.conf
[SeatDefaults] pam-autologin-service=lightdm-autologin session-wrapper=/etc/lightdm/Xsession autologin-user=username autologin-user-timeout=0 autologin-session=true
Then as root (#):
# groupadd autologin # gpasswd --add username autologin
reboot
Hope this helps someone else.
-T