Overall an interesting piece. I didn't quite understand why he's raising the question of why happiness is the ultimate moral good. While I understand it's contentious, when talking about the repugnant conclusion one typically deals with that assumption so as to contribute useful dialogue to the discussion.
I agree with questioning why happiness is the ultimate moral good. Shouldn't it be minimizing pain? Because let's face it - humans are a fickle, fragile animal. Some of us have physical issues that would, generally, 'lower' the happiness of humanity. But by trying to reduce their pain, it may have an impact. Isn't most unhappiness caused by either pain or illness anyway? (Though I have to say - this is one of the reasons philosophy tends to rub me the wrong way - both excerpts tend to much simplify complex problems, and often purposefully turn a blind eye to some rather obvious issues, and some very real situations - like when the piece commented on Somalia)