Microsoft SyncToy is a nifty little program for keeping folders in sync. although its downfall is it does not copy file permissions I have used it to migrate large amounts of data from server to server preforming a final quick sync just before editing login scripts to the new locations. I also use this at home as a handy way to backup my files to my portable hard drive.
Download Microsoft SyncToy: http://www.microsoft.com/download/en/details.aspx?id=15155