The video shows how to grind sludges in Maraudon using AoE. The spot can be used by both mages and warlocks, the movie shows how to do it using a 53 warlock (all same skills as level 50) with dark pact. Well over 100k xp/h can be sustained at level 50.
This isnt the first Maraudon-AoE movie, but some of the others ive seen are waaay too slow.
Edit: This technique can no longer be used, since XP from the sludges was lowered (now its nearly nothing). .