I really hope they bother with one more match at least. It was a pity human vs computer idea basically died in chess after very unconvincing win by Deep Blue (even though it lost 2 previous matches). Humans had at least a few years more of good resistance back then.
I can think of a worthy goal for AlphaGo: make a program which can play better than top pros which runs on a macbook pro.
Closer to their goal: Make a generalized AlphaGo program that runs on a computer no heavier than 3.3 lbs and uses less than 20 watts of power. Macbook pro is currently 30 watts and 4.5 lbs. So, that's pretty close. But the parent company, Google DeepMind, doesn't have go playing as their ultimate goal.
I can think of a worthy goal for AlphaGo: make a program which can play better than top pros which runs on a macbook pro.