Great article on abandoned cities in MMORPGs as World of Warcraft.
The only thing I would like to add here is that Darnassus was never really crowded (and I liked this).
With yet another expansion in the works, there’s no doubt that the boom and bust cycle of WOW’s cities and wilds will continue. Players will move on to new places for new quests and leave behind the spaces where millions have spent countless hours. Those empty expanses will remain intact, pristine despite their abandonment. That perfect preservation makes these ghost towns all the more eerie, but in the silence is a chance to see the quiet beauty that was there all along.