I had three others suggestions, but this one is more important: A document viewer.
In Windows (at least Windows 7), you can (pre)view the files you are renaming without having to open them, with the document previewer. In Windows, it's the small icon just to the left of the "?"-icon. This is extremely handy when renaming files as you can easely scrool through the documents without having to open them all. If this could be added to Bulk Rename Utility, it would really have an impact.
Best regards,
Thomas, Copenhagen