I remember I watched the spurs vs hornets game, and he got like 10 pts in first quarter or first half. You are right. He is not as often used as last season. I guess that is because Pop likes to play the small ball a lot this season. But, when opponents have big men, like shaq, Yao, or Tyson Chandler..., they still use him a lot.
I think the top two teams i.e. SAS and Dallas can still be playoff team without the star, Duncan and Dirk. I am not sure about the rest.