He's in the Horde Garrison giving the PC commander orders to build a shipyard and invade Tanaan. For the Alliance it is either Yrel or Varian taking his place can't remember. He also set up the Horde advance into Ashran and assigned Volmar the general.
Just because he isn't in the front lines swinging a hammer doesn't mean he isn't leading. He's a more diplomatic behind the scenes Warchief.
Also, the dudes been Warchief for like... 1 year game time. Cut him some slack.