I use Photoshop mainly for front-end web dev. The most common use of it is just slicing up images to be used, having it work on a retina display would be great. It's so common for cutlines to become blurry the more you zoom out on an image, so I think that having it be 1 to 1 pixel density is a must have. I don't believe that since the pixel density is higher in the images, that the actual controls can't be retina friendly. Isn't that how Final Cut works on a Retina Display? I don't have either, but I remember Apple stating "In this window, you are seeing a full un-altered 1080p frame, along with the controls"