Hey all, not sure if anyone has discovered this yet but I'll just give a quick description for those who haven't:
Was in Heroic Stonecore the other day, and hit Flame Orb by accident before the tank pulled. As soon as the orb got close to the boss he dissapeared. Naturally, we just laughed and ran straight past him. We then did this to the next boss, and I've also tried it in Vortex Pinnacle and it works on the first two bosses there as well so if nobody needs gear from these bosses you can basically just skip over them which is quite funny:P
Well anyway, it's probably well known and will be fixed today, but hey just wanted to share the neat trick.