The current trend is for many user-selectable images, e.g. profile pictures, to be displayed in a circle rather than a rectangle. It would be great if there was an option for the crop guide overlay to be a circle instead of a rectangle so the user can ensure that their image content won't be cut off by the clipping of the circle. Obviously in this case, the image would actually crop to the bounding square around the circle, but having the crop guide overlay a circle would eliminate the guess-work around whether important bits will fall within the circle or not.
Is this possible via a work-around currently? Is this something you would consider adding to the image editor control?