Heres a way to skip the annoying adds and wait time before Hadronox in Azjol-Nerub heroic. This method requires a mage/rogue/hunter.
Mage/Rogue/Hunter run into the first pack of mobs and Invis's/Vanishes/Feign Death as soon as they get agro. This causes the first three packs, and all the adds that Hadronox kills to despwan. Now with patch 3.3.2 these mobs come back when you engage Hadronox after this exploit, simply have the mage/rogue/hunter re-engage the boss, let the adds rush in, then vanish/fd/invis and then Hadronox will begin attacking the adds, have the tank pick him up when there are 1 or 2 adds left.
Hope this helps with the recent 3.3.2 nurf!