wasn't there a recent string change for names to allow apostrophs and spaces? With guild name changes becoming ingame gold, player names might be comming soon to, with more RP friendly options like last names or using apostrophs to mimic iconic names (Kael'thas, Kel'Thuzard, Vol'jin)
This, housing, potential for races, Midnight might be the most RP focused expansion. Perhaps to mimic legions class focus, Midnight will focus on RP