So having played with WP 3.5, I’ve come to the conclusion that the media management is still lacking. I love the new way to create image galleries; and I really like the way you can resize/scale images directly on the image detail page. But I was really hoping for a way to checkout/checkin images. Currently, you have to delete the image and upload it (with the same name) if you want to change an image. This probably doesn’t affect most people, but a lot of development I do is done with storefronts. Customers are frequently updating photos of products. This part became quite the pain. However, I discovered this great plugin that does exactly what I want – replace existing image with a new version. Granted, it doesn’t do revisions, but that’s ok with me.
Check this one out sometime: http://wordpress.org/plugins/enable-media-replace/