There is always the initial Hype to start a new alt and at least reach lvl 20/30 after that people usually quit. And of course every new player contributes to populating the zone (plus the server changes now). I always used to find a group of new players at Duskwood, Tarren Mill, Westfall, basically all the initial level zones until stranglethorn vale at least had a group on them. And always gave the true experience of leveling to people. I bet every new player now just queue up in main city...
But guys I don't know if the answer to bring world pvp back is in the leveling zones. I always hoped blizzard implemented some kind of stuff to bring players with level cap to the world. Like....Gurubashi Arena, Dire Maul Arena, stuff with updated rewards that everyone wanted. The presence of events like this through out the world could easily create hubs of people and partys from both factions populating the zone for infinite times. (people still go to gurubashi arena just for the lols so imagine new updated rewards in this chests.)
Just an idea what you think?