AppleIsider says that Apple is to drop Samba networking tools from Lion and replace it with Apple’s own tools for Windows file sharing and network directory services.
Samba’s improves interoperability between PCs with Microsoft Windows and computers running other operating systems. Notably, the software enables UNIX-based systems like Mac OS X to speak the Server Message Block (SMB) protocol that Windows uses for file sharing and network directory services.
Apple began bundling Samba with Mac OS X 10.2, enabling Mac users to connect to Microsoft’s Windows file and network directory services based on SMB (Server Message Block, a protocol also known as Windows File Sharing).
Read more: http://www.appleinsider.com/articles/11/03/23/inside_mac_os_x_10_7_lion_server_apple_replaces_samba_for_windows_networking_services.html