Haha, I was just browsing the gallery and immediately came to the Suggestions & Feedback forum to request this exact feature. You beat me to it
I really believe that we should be able to manage our uploaded images the same way we can manage our posts and attachments. We should be able to delete our own images or modify their attributes (gallery, title, comments, etc). I know some of my images aren't really worthy to be in there.
There should also be a quota of the number of images allowed per user (or megs per user). An upper limit of 20 images seems reasonable.
I'd really appreciate some admin / moderator thoughts on this.