I have a prediction that in next week's episode that after finding out what Clay has been up to with the NOMADs and the home invasions, Jax is going to kill Clay in the heat of the moment without thinking of the consequences. Clay's death will create quite the mess for Jax when Clay's presence is important to the CIA/Cartel arangement. It may also create some heavy tension in the club. Juice may be afraid to suffer the same fate as Clay if Jax ever found out that he turned rat for a time last season.
I just don't see Clay being around for Season 7 or beyond Season 5.