When I go to set a new header image for my blog, I have to select a file from my computer and upload that, I can't select one of the images already uploaded for use in my blog.
I would like to see the choosing/uploading of a custom header image merged with the existing upload manager. That way, I can just upload a couple of header images and when I want to change the actual header image used, I can just pick one of the header images from the image selector. Everything blog related would be stored in one web-accessible place (on WordPress.com) instead of two places, one of which I can't access when away from home.
(I'll send this to Support as well; just wanted to share the idea)