F2 is program for automating the process of renaming files. I wrote it to cope with the thousands of badly named mp3 files I have, but it can be used for just about any rename purpose. You can use regular expressions to parse the FileNames, and use tagged expressions to generate the new filenames.
F2 shows you exactly what it is going to do before it does it, and supports full undo of renaming if you don't like the results. There's some rough edges at the moment, but it works well enough to use it. Soon I hope to add history buffers to THE Rename fields (so it remembers your regular expressions, etc), and possibly after that I will add some more sophisticated rename features.