I don't know - since Aquir threat was eliminated back in Vanilla and in Cataclysm zone wasn't changed its kinda hard to say if anyone still maintain garrison in Silithus.
Next Arms Warrior artifact weapon in 8.0 confirmed.
WHAT? Silithus one of the most atmosphere zones in whole WoW and last bastion piece of Vanilla!!! BE GONE TRAITOR!!!
Sorry couldn't resist...