Motivation:

Having priority categories is fine. But often it is not granular enought to assist in work scheduling, whereby tickets should be processed in a particular priority order, which may change fairly often as new ticket appear.

Solution:

Enable tickets to be dragged and dropped to enable relative ordering of tickets. Drag a ticket up and above other tickets to increase its priority. Drag it down to decrease it. Have an option to shows bugs in "detailed priority" order on reports. Keep a track of the drag and drop order at all times.