They are the fists of the Warchief, whoever he is. They are the sworn honor guard, the advance force, the first into the fray and the last to leave. They are Kor'kron. What other forces in the Horde can aspire to be they have already been. Since the founding of Orgrimmar, they have advanced the cause of the Horde anywhere the battle has been joined, fighting against Illidan's forces in Shadowmoon Valley, pushing against the Lich King in Northrend, throwing the traitorous Varimathras back to the pit in Undercity. Now you can find them seeking to drive the humans into the sea on the new islands near Vashj'ir or fighting the Twilight's Hammer in the Highlands.
They are Kor'kron. They know only victory or death. Their loyalty is absolute.