This entry about managing staging folders gave me a tidbit of information I didn't know/realize about DFS and how it differs from FRS. DFS (Win2k3 R2+) uses the staging folders for inbound and outbound.
As broadband becomes more available, you will see more and more reasons to use DFS for multi-site companies, even the 2 location Mom-and-Pop shops. It was hard to do, decently, with the older architecture but these new features make it easier to achieve. You could almost think of the data going over the wire as "compressed block-level differentials". That is a big win when going over a VPN or a cable modem.