My idea is that wordpress should manage image just like it manage post.
Imagine : you write a post, upload one or more image and that's it. WordPress should put one of the image (maybe randomly) at the top of the article (thumbnail or full size) and add a thumbnail galery at the end of the post. or you may have some predefined template for image integration in post.
Plus, if wordpress manage image this way, add the ability to display a last image galery in the sidebar or elsewhere (one image per post, or a selected number of last image)
This way publishing post with image in a wordpress install would be far more simple than actually.