I'll have a go at a solution, but I'm a mac guy

, so this is all in theory...
A quick google found
this utility to rename files using a text file as an input. I have never used it, and I am sure there are others. But since this is the first one that I ran into, we'll use it as an example.
I have attached a space delimited text file which has the romname first, then the game name. This was easy for me since I have the mame xml info already loaded into a database that I will be using for my arcade.
So, in theory, you should be able to load this text file into the afore mentioned utility and have it change the filenames to the actual game name. Then you can use Photoshop to add the file name. Then use the text file again to re-rename the files.
*[EDIT]* I just realized that the change-to names would contain spaces, so you will need to find a utility that will allow spaces in the filenames.
It sounds like a long shot but it may work. Make a copy first, obviously, in case something goes wrong. Also, you may want to get rid of the file extensions somehow, since they will show up in photoshop. Good luck! Let me know if you need the text file in another format.
Also, if you have access to a mac, this sounds like it would be pretty straight forward using a combination of Applescript, Automator, and possibly Photoshop...