I was thinking along the same lines. Related Docs, Categories, Search and Taxonomy are huge pluses. When we started developing the site the image store was already available, now I feel it is time to integrate it.
How would you go about allowing users to just upload images as attachments ? They do not have access to back end. Right now I have a custom web part that I would have to modify to use the attachments API. Unless there is a simpler way, I really couldn't build one out of the stock web parts.
Also if I wanted to capture UserID of uploaded user, should I just mod the Attachment table ?