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)
Darien is a city in DuPage County, Illinois, USA. The population was 22,086 at the 2010 census. A suburb of Chicago, Darien was named after a town in Connecticut. The town motto is A nice place to live which happens to be the same town motto as Hill Valley from the Back to the Future movies.