Wow, amazing. Sick of seeing Samba 4 build in repositories yet more or less useless, due to support. It will be good to see this released, alone with PulseAudio 2, Gimp, etc, into the mainstream.
This needs to be nicely integrated with distributions so it "just works" out-of-the-box and be very easy to use.
The enterprise distributions such as Red Hat and Novell should definitely focus on Samba and Samba integration and stuff such as LDAP, Active Directory, Exchange, domain login, domain joining, single sign-on (SSO), group policy, network access protection, thin clients, updating from a local intranet server, IWA / NTLM authentication, etc.