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)
1 Anyone at any level with 2 can get to Dalaran as of Patch 4.2, as all players now have the Dalaran flight path by default at player creation time. 2  Take a ship / zeppelin to either Northrend port; then speak to the flight master on the dock and pay 2 to get to Dalaran. Anyone who is at least level 74 can get [74] The Magical Kingdom of Dalaran from any of several members of the Kirin Tor, which will portal them to Dalaran until you complete the quest. 2  A set of crystals, (Teleport to Violet Stand Crystal and Teleport to Dalaran Crystal), can be used.