SSSD now (as of F17) has support for automount maps (considered experimental, and requiring the installation of the libsss_autofs package), but authconfig doesn't know how to configure it.  There's this from authinfo.py:

# Now replace sss with ldap or remove it
# in all non-user info entries - this might be changed in future
# if sssd is able to provide automounts, netgroups, and so on.

which I just suppose needs to be (perhaps conditionally) disabled for the automount: line.  Additionally, "autofs" needs to be added to the services line in the sssd section of sssd.conf.

In my particular installation, I also have to tell sssd the format of my automount maps and entries in ldap, because I'm using the old NIS-based maps.  This means I get to add the following options to my domain in sssd.conf:

ldap_autofs_map_object_class = nisMap
ldap_autofs_map_name = nisMapName
ldap_autofs_entry_object_class = nisObject
ldap_autofs_entry_key = cn
ldap_autofs_entry_value = nisMapEntry

And while it would be doubly awesome if autoconfig gave me a way to set that, I certainly wouldn't blame anyone for telling me to take care of that myself.