If implemented, it would probably be desirable to make the wheel do what makes the most sense in a given context. When the pointer is touching the map, a scroll-zoom would be similar to the functionality in Google Maps, for example, to which which many users would be accustomed. However, when the pointer is over another part of the window that contains, for example, a list, such as the initiative order, many users would expect the wheel to scroll through the list.