Saul + Erica (spoiler)
I never took Erica's refusal to spend the summer with Saul at his Vermont place as her breaking off the relationship. I took it to mean only that they'd be separated for or 3-4 months, but the relationship would continue. She also said she expected to spend time with him while he was away; and Saul certainly could've come back to spend time with her during that period.
So I was surprised when both Mazursky and Clayburgh said in the DVD commentary that she broke with him. I never took the ending to mean that; only that she was not going to order her life around her relationship.