I think it would be good to start a discussion about this setup here. I can't be the only one experimenting with this. I was disheartened when I've learned that Lion server could not act as a NT server anymore. But with SAMBA4 reaching its beta stage recently I've gave it a try today. The machine used was a C2D Macbook White I had lying around with 4GB memory (sadly it only uses 3.5GB memory) with Lion and the latest Server package from the Store. The Samba4 Domain Controller is an OpenSuSE VirtualBox VM running on the same hardware with just 512MB RAM and 8GB disk. The latest release of the SAMBA4 suite is in the first beta stage and it includes the directory, kerberos and even DNS through their new DLZ plugin. All those services can be managed through the Administration Tools package downloaded from Microsoft. I've also edited some stuff through phpLDAPAdmin like adding posix attributes like loginShell, gidNumber and uidNumber. And the good news is that everything works. I was able to bind the server machine and integrate it the Server applications with the SAMBA4 DC just as it would with Active Directory. It is soon to use it in production environments but I think its a great idea for a home networking if you have some knowledge with Linux or FreeBSD.