FileWrangler 1.1 has been released which is an update to the freeware OS X application for renaming batches of files easily. Select a folder, filter its contents, recurse its folder structure, choose your naming scheme and click the ‘Rename Files’ button. Dozens, or hundreds or thousands of files are quickly renamed to meet your criteria. It’s a problem that has been addressed by other applications, but none work quite like FileWrangler. Pure Cocoa, written in Objective-C, and fast.
More info and download link here.