This one really surprises me. Microsoft, (albeit under court order) has begun working with Samba’s developers to ensure proper interoperability between Active Directory and Samba.
For those of you not familiar with it, Samba is the open source implementation of the Server Message Block protocol, also known as SMB. It’s a way for non-windows computers to communicate using Window’s native language, SMB.
This is really fantastic news, as the biggest reason that implementation of Linux or UNIX into a heterogeneous Windows environment is problematic at best is the lack of a single point of administration for user accounts.
(And, currently, AFAIK, there’s no built-in password synchronization to Active Directory for Linux and UNIX users. Sure, you can script it, but that’s messy…)

According to this article, Microsoft is treating the Samba developers as “Premium Support” customers, and cooperating fully, even devoting the resources of knowlegeable developers to answer relevant technical questions for the Samba team.

So Microsoft, THANK YOU!!!
Interoperability will benefit us all. Thanks for doing the right thing.