While waypoint answer the problem of traveling between distant levels/areas, there is still vast distance to walk/run within a level/area/instance itself(which is wasted time).
A teleport beacon system is essentially one-way auto-teleport from LocationA(the Beacon) to Location B(the Destination) acting like a permanent one-way portal.
Advantages:Reduces travel time, allow fast retreats or attacks, makes mass movement of parties/clans faster.
Possible improvement: allowing players to construct their own beacons as custom waypoints if the area has too few of them.