DOM Level 3 Events defines mouseenter/mouseleave hit testing transition events.[ These events are different from mouseover/mouseout in that the mouse has not "left" the element simply because it went over a child (and the events do not bubble). This makes mouseenter/leave the event analog to the CSS :hover state.
Pointer events should support this concept via pointerenter/pointerleave events (supporting multi-pointer interactions as well). [3,4]
Per 12/4 telecon resolution, making this change as suggested.