I use OS X Mountain 10.8.2.
I used Automator and added AppleScript, copying the command from the old app's developer at the Iconoodle - Convenient ICNS to PNG image conversion (Iconoodle isn't supported by OS X 10.8 by being a PPC app). I saved the workflow as an application. I selected the images and dropped them into the application, but the images weren't converted to ICNS. I also copied from the question Convert image to .icns file AppleScript Obj-C from StackoverFlow and it didn't work either.
I'm really frustrated with it. I want to use Automator to convert the multiple images from PNG to ICNS once at all. It's very annoying to convert each image to ICNS in the icon editor applications, one for one. The Preview.app doesn't want to convert the image in format PNG to ICNS because it has only one page, it can convert it to ICNS only if the icon has many pages.
Do you know to make it?
Thank you for your attention, help and patience!