When the user selects to authenticate via NIS, it'd be nice if authconfig would do a complete update of the nsswitch.conf to use YP. Currently, passwd, shadow, and group are updated, but netgroup, automount, and aliases are not. There are reasons to not use aliases, but netgroup can't come from a file, and automount would be a nice touch.
Should be fixed in beta4. Please reopen if this is not the case.