I'm considering a sprite packing tool, the one where you pack multiple sprites into one or multiple images for LoadSubImage. I have a couple of feature ideas to look at when it starts.
I don't mind if others are planning on the same, or similar.
after a few other ideas escaped my grasp for this, i'll be submitting a subimage editor as well :) mine sounds different from yours but along the same lines. regardless, the more the merrier!