Hi ShadowsDweller, I have a couple of suggestions or feature requests for this plugin, for your consideration:
1) It would be nice to have the option to limit this plugin to only administrators (or only users above a certain role), in the event that I don't want certain other users from being able to rename media.
2) The description at http://wordpress.org/plugins/media-rename/ explains that since version 3.1, "the plugin will not only loop through your posts' content, but also all your metas and options". This sounds risky (???) - and if it is risky, maybe it would be useful to have a setting for the plugin, to turn off the "metas and options" replacement and only do a replacement in posts/pages content? I guess only replacing the file name in pages/posts is a lot safer and maybe there isn't any need to also search through the metas and options in some cases?
(To be honest I'm not even entirely sure what it means to search through "metas and options" - maybe you can give more info on that)
3) Could you envision giving your plugin the ability to move the selected media file into a subfolder, as an option? So the user can select or type in a subfolder name which is inside the main media folder (or maybe select a pre-configured subfolder), and the media file is moved there, and/or renamed if necessary. This would be a great feature to have!
I guess for these ideas you would need an actual Settings page for the plugin to configure it.
What do you think?