Okay after watching the finale I have to take SOME things back that I said but I still believe that the second season will be much more promising. They'd already filmed all of the show before it aired so there was no way to react to feedback in any way.
And I still think there's plenty of potential in the world of Shannara, especially for Eretria and Amberle. I hope you guys don't give up on it.
So I marathoned Shannara over two days now and I must say I enjoyed it far more than I expected to. Manu Bennett as Allanon was just brilliant. As for Amberle and Eretria, I enjoyed their interactions immensely but I'm not hopeful that anything more will happen, even if they made season 2, since it was mentioned that in the books Will and Eretria are the endgame. Plus their children are the protagonists of the next book. Not to mention the fact that Amberle is the Ellcrys now. I dunno, maybe I'm just being overly pessimistic.