The Microsoft File Server Migration Toolkit page begins with:
Many organizations today are migrating and consolidating older file servers to reduce total cost of ownership (TCO) and increase the efficiency of storage management and backup tasks. Microsoft Windows Server 2003 technologies deliver low TCO, reliable file services essential to enterprise computing infrastructures, and an exciting set of customer-focused services to increase return on investment (ROI) and enhance end-user productivity.
To make the file server migration and consolidation process easier, Microsoft has released the Microsoft File Server Migration Toolkit. In addition, Microsoft has released guidance for file server migration and consolidation as part of the Solution Accelerator for Consolidating and Migrating File and Print Servers.