Boxing & unboxing is the process of converting a primitive value into an object oriented wrapper class (boxing), or converting a value from an object oriented wrapper class back to the primitive value (unboxing).
The Old Dalaran will stay in Northrend, so yes, mages are going to have 2 portals to dalaran (one to Northrend and one to the Broken Isles)
River Dargle. The River Dargle (Irish: An Deargail, meaning little red spot, so called with reference to the prevailing tint of its rocks) rises in the Wicklow Mountains of Ireland on the northern slopes of Djouce Mountain and flows over the highest waterfall in Ireland, falling 121m (398 feet) at Powerscourt Waterfall.