Selecting LDAP authentication in the installation seems to correctly
configure nsswitch, but not pam. The result is that LDAP users and groups
can be seen, but you can't log in using your LDAP account.
This works for me in the current internal build.
Passed to test lab to get more details about bug and to verify works against
this is fixed internally ... thanks for your report!
(BTW, for beta2 you can enable LDAP as your login service by running authconfig
after the install, and at the second screen select 'Enable LDAP authentication'
... an initial implementation had us installing and configuring for ldap, but
not actually enabling it ... this will be changed for the next beta, though!)