I feel that having the ability to edit the poll description of an ongoing poll would be quite useful. I understand that there is not much of a point in being allowed to edit the question when you could just delete it, but I feel that editing an ongoing poll description would allow the pollster to add extra information or references to their poll if they see a need after the poll has been going for of couple days.
Maybe even the ability to add an additional voting option as well would be equally useful for the same reasons above?