Quick update: I installed 10.5 on a system at work. We use LDAP for authentication (and directory services) and home directories mount over NFS.

Tiger will work out of the box with this (sees the 'open directory' [LDAP] server and asks if you'd like to use it and will mount the home directory without trouble), but with Leopard there may be a catch even if it sees your LDAP server and is happy to use it for authentication. If your home directories mount, as ours do, to /home you'll need to edit /etc/auto_master and take out the dummy mount for /home already in there. Otherwise, it works like a charm for us.

DOesn't work for you? If you have trouble authenticating using your LDAP server (or if you have a non-standard schema in place), you may have to manually add your server in Directory Utility rather than rely on it coming from DHCP if you can't authenticate or the entry says the LDAP server is not in your authentication search path. If that's the case and you still have trouble, click Advanced Settings and manually add (custom) your Authentication and Contacts in the Search Policy pane.

And NetInfo is gone, baby, gone. ;)

PS - http://www.mac404.com/