At a couple points during beta it was superior to grind mobs for the first 1-3 levels, while your scaling was still high, then swap over to questing. Of course, these were also passes where it was possible to run out of quests and not be level-capped
But pocketing some quests for level-cap can still be useful, since the quest reward items will scale up in ilvl. Of course, time-wise, you'll probably outstrip that gear rather quickly just by doing world-quests.
In it's current state, just leveling naturally following your questlines and returning to your Order Hall every level or two (so either half-way through each zone, or at the end of each zone) to check on what new events have popped up seems best.
I doubt doing dungeons while leveling will be worthwhile unless you have a friend or two tag-along with you; will be a lot of derpy, slow-ass dungeon runs since people'll be getting used to the new dungeons. Many of the new dungeons have irritating (not threatening, just time-intensive due to superfluous adds) trash pulls if your group is a pile of random derps.