A great video is making the rounds right now of an exceptional player using some unintended consequences to solo multiple bosses in Mogu'shan Vaults -- and as a protection-specced paladin no less! He apparently downed Stone Guard, Feng, and Elegon before Blizzard caught wind of the escapade. You can see a video of the Elegon kill above.
How he pulled this off was by taking advantage of a series of design choices that Blizzard made, combining them all into a hilarious example of the law of unintended consequences in action.
To reach a decent item level, the paladin equipped various bind on equip rares that drop in Mists zones which all had a required character level of only 80. And because he was only level 80, he was avoiding the combat ratings drop-offs for levels 81 and 86 that a normal character wearing those pieces would be subjected too. This would allow him to get an insane amount of secondary stats like haste (I've seen that he had 95%!) and mastery (88%, apparently).