Should Korrak the Bloodrager make a return to the Field of Strife, seek him out and destroy him. Return the Skull of Korrak to Warmaster Laggrond in the Hillsbrad Foothills.
While it is true that Korrak has been slain, one question remains: Will he remain dead? Trolls are notorious for their other-worldly tribal magics. I would not be surprised if the fallen leader was raised from the dead to once more rule over his clan.
You know what to do should this ever occur.
<Warmaster Laggrond makes a cutting motion across his neck with his index finger.>
And this time, I want his skull. Just keep your eyes peeled, soldier.