Matthew Rossi over at WoWInsider touched upon the Nazgrim thing in a couple of his recent articles. I thought he had it all covered in one of them but it seems there are just pieces of his thoughts on this development scattered in several of his posts concerning the Siege of Orgrimmar. So it's rather useless to link any one of them. I think what he wrote boils down to Nazgrim not being loyal to Garrosh but rather refusing to abandon the Horde. Even if he disagrees with its policies.