The Media Library, or at least media handling, is finally slated for an overhaul after almost 4 years! Whether this involves only a redesigned user interface or streamlines the media handling workflow we won’t know until it’s introduced here on WordPress.com for beta testing*, which does not seem to be anytime soon.**
Besides the, in my opinion, unwelcome addition of infinite scroll in the Media Library, there will be far less visual clutter and fewer wysiwyg image editing options, as the “Advanced” tab on the in-post Edit Image dialog box will be removed.
After reviewing the proposed Media handling slide show, the obvious missing features that stand out for me so far are the lack of an ability to bulk delete images, the removal of the image description field (whether an oversight or by intent) and the potential difficulties involved in working with a large number of Gallery images in a large thumbnail, drag and drop, infinite scroll environment. Unanswered questions I have are whether it will be possible to add multiple Galleries to a post or page more easily and whether it will be possible to attach an image to more than one Gallery. Also, with the removal of the image editing Advanced tab, how will image CSS classes, borders and spacing be handled, if at all?
Again, this proposal is preliminary, an ongoing work in progress and, as advised, nothing has yet been set in stone. If you’re interested, you can follow the discussion on make.wordpress.org
*Many features of pre-release standalone WordPress are incorporated into WordPress.com first for final testing and user feedback. While this is no secret, like site-wide advertising, it is also not talked about frequently and WordPress.com covers this aspect of the site in the Terms of Service.
**WordPress 3.5 is expected on December 5th this year. (hat tip to timethief)