Photoshop has an action called Retinize It for making Retina Display images, after reading Retinize It: Free Photoshop Action For Slicing Graphics For HD Screens at Smashing Magazine I though it might be possible to have a similar script for Gimp. Retina display use is only going to expand so a script would be great, especially for web designers. I was hoping one of the programmers could have a look into it?

Towards A Retina Web
Designing for Retina Display

I don't see what his script does that could not be done by scaling the image by 200% first and using the regular script?