Put it this way. Garrosh was made warchief as the cataclysm began. Do you think he immediately took the mantle and shouted "PLAGUE BOMB SOUTHSHORE AND BUTCHER ASHENVALE." Cause guess what? He didn't. He did so faster than Varian would, sure. But that's his character. I would not be in the least bit surprised to watch a few major horde outposts fall to the Alliance while the Horde re-structures itself under the new Warchief. Varian has the strategic advantage now, and he knows it. Now he just has to act on it.