I would like to see more NPCs travelling along the roads in zones from one zone entrance to another. It would make the world seem more lively. Dynamic events could be attached to them, but not necessary. At night, you could have Lionguard patrols with torches and NPCs that pitch a tent and make a fire like those memento collectors in the living story and then keep moving during the day.
What I would really like to see is travelling merchants/circus/refugees/supply caravans that moves across zones to different destinations across Tyria. I know this can’t work because the zones are not synced.