Nice additions to Samba 4 is a built-in LDAP back-end and Kerberos encryption that is compatible with Microsoft's version. Linux Format has an interview with Jeremy Alison, a Samba developer. He talks about the long development process that has taken place and is still to come. The Technology Preview includes a good deal of the AD server functionality but still lacks printer and security features, plus the back-end LDAP structures are in flux. Still it is pretty exciting, maybe OpenSUSE 11 will feature Samba 4....