For the last couple of years I've presented at Microsoft TechED about the use of DFS (and hope to present this year as well covering the changes in R2).
I can't see why there has not been a greater uptake on DFS and can only hope to talk to more people and maybe supply some pointers that may make it easier to deploy.
For those new to DFS, start looking here. If you would like more information please email me.
First piece of advice. DFS works well on Windows NT4/Windows 2000 servers and Windows 2000 clients with caveats around some of the functionality (Offline folders, DFS namespace limitiations etc). If you do not intend to use Windows Server 2003 as the DFS Root (link targets are not a major issue on downlevel Windows servers or SAMBA boxes) and Windows XP clients then my advice is to use DFS to provide an abstracted server namespace for documents. For example if you have a number of servers holding documents you can put DFS infront to provide a more consistent address space for your users and also more flexibility to move servers around (decommission etc). If you are using Windows Server 2003 DFS namespaces and Windows XP clients then you can look at more system processes using DFS (Offline folders / Folder Redirection etc).
Second piece of advice. Become comfortable with how DFS masks the underlying file system. A DFS link target could be published as \\company.co.nz\DFSData\Users and it could point to a UNC share and path of \\server1\Data\NZ\Users\TroyK. In a traditional UNC environment the folder could have been shared as \\server1\TroyK$. When troubleshooting DFS issues (esp with Offline Folders / Folder Redirection) it is important that the permissions are checked at each layer of the path. In this example for Offline Folders to work the user would need LIST permissions to \\Server1\Data and the NZ and Users folders and then WRITE/EXECUTE etc to the TroyK folder. This can be one of the more frustrating learning curves for IT staff.
Third piece of advice. Read the background articles on Offline Folders / Folder Redirection here and the DFS support matrix here (esp the Can I use DFS with Offline Files and redirected My Documents folders? question).
Fourth piece of advice. Understand your data and replication. Shared read only data can be replicated more easily than shared read/write data. Also plan the impact on your network. This is one area the R2 release of DFS should be a major boon.
Fifth piece of advice. Give it a go. You'll hopefully be amazed with how easy it is and there is always good resource on the internet or email me to see what I can do.