I put this together for the eXodus website, but just in case anyone else wants it I'll leave it here. This is a windows-only executable .jar that creates a sprite sheet out of the PA unit icons along with a json describing the position of each sprite. To create a new sprite sheet after the game is patched, unzip this to anywhere you want, then just run the jar file. I'm just using http://spritesheetpacker.codeplex.com/ and then converting the .txt output to json.
