The ability to paste images
I'd love the ability to paste images, either grabbed with
Print Screen or with
Ctrl+C from Photoshop or some other editor. Or even right-click -> copy image from the internet.
I often find myself using half-finished assets in my projects just to see how they look overall, and having to export it to a file each time, or save on my disk, before being able to use it is a bit bothersome.