David Golds passed along the following link to a Windows Server 2003 R2 DFS white paper:

From the download page:

Overview

As organizations expand to include more users and servers—whether they are located in one site or in geographically distributed sites—administrators find it increasingly difficult to provide users with intuitive, fast access to the files they need. Administrators who manage remote or branch offices face additional challenges, such as limiting network traffic over slow WAN connections, ensuring the availability of files during WAN outages or server failures, and ensuring that branch servers are backed up correctly. To help administrators address these challenges, the Distributed File System solution in Microsoft® Windows Server™ 2003 R2 provides two technologies, DFS Namespaces and DFS Replication, which, when used together, offer simplified, fault-tolerant access to files and WAN-friendly replication.

thanks David!