To the people saying he got off easy:
It is not the law's job to get revenge for the victims, but justice for the kid. Stop thinking about all the dead people and think about the decisions the kid made. He took drugs, drank, and drove. I'm sure more than half of America has done all three of those things (not necessarily simultaneously). The point is, he did nothing malicious. Sure, he made a colossal mistake, but he has to live with that. If it were me, the guilt, regret, shame, and emotional stress would be worse than any punishment a judge could come up with.
I think the punishment is just.