That 2nd link is an obvious straw man. If you read what Gates is actually saying [1] it's far more reasonable. There is a huge dynamic range in teacher abilities. He is saying take the very best, and give them a slightly higher load. Just as you can take the very best programmers and have them write more code. But then people freak out and say Gates wants big classes across the board, it's silly.

[1] http://www.washingtonpost.com/wp-dyn/content/article/2011/02...