A little bit amused, but not shocked by anything anymore how easy people get excited over not only simple things, but things that already exist, and are 100 times better, in the meantime not addressing the real issues and WordPress's shortcomings.

There is a plugin called "Image Widget" at the repository, but it's only for images and not video or audio files.

BUT, there is a plugin called WP Editor Widget which is truly the perfect Swiss army knife for widgets. It's basically a text widget with the full TinyMCE editor available. Add media, shortcodes, and basically anything you can do in a post or page. This plugin should have been selected for the core... but again, what do I know?

I would instead put all of the available resources to tackle the security issues, before doing anything "spectacular" like this, or distraction free writing !!!