Inside TJS, directly ahead of the zone in in a temporary under construction gate. You can jump over this and find 3 packs of mobs fighting npcs. Each pack contains one strong elite and 5 weaker elites. Each of these mobs can be single pulled, and give up to 60k non-rested experience when killed (experience varies due to npcs damaging the mobs). I was able to gain 1.1 million experience in 7 minutes (non-rested) including doing the two bosses which I defeated using the Doom/Maelfic Grasp bug mentioned here: http://www.ownedcore.com/forums/worl...ck-damage.html ([beta] New method for insane warlock damage.)
Consequently, this is useful if you just want to do the last two bosses, as the first two often don't drop loot or are bugged.
Video:
Mists of Pandaria Beta - Jade Temple Fast Experience - YouTube