The ability to include an image upload box as an extra field. The box would be basic like the current image field, but this would be for additional images with no resize functions.
Reason: I am working on a site right now with heavy design features and has a team member gallery. The thumbnail of the team member is small square headshot, but the large image is a picture of the person in action and takes up the full header of the details page. As a solution, I use a regular extra text field by entering the image name. I have the template setup to accept this extra field in the header area and just setup the image tag around it
Even if the field just uploaded the image and outputs the image path/name, it would work for any heavy custom template designers.