We're in the process of moving from NIS on our Linux systems to binding everything to Active Directory. The NIS environment follows the common standard used by many Linux distributions that a user's primary group is a group of the same name as the user (and of which the user is typically the only member).
I have been informed that in the Active Directory environment, you may not have a group name with the same name as a user (specifically, that no two AD security objects may have the same name). This would seem to complicate the process of moving our group definitions into AD. It looks like we could maintain the NIS group information in AD using only POSIX attributes (e.g., not an actual AD security object), but that seems like a suboptimal fix (because we do really want to have the same view of group membership in both the Unix and AD worlds).
Have you moved a large legacy NIS environment into Active Directory? How did you handle this situation?