Interesting that they say he's not enamored with vouchers - seems he just thinks it's unlikely he'll see them supported & implemented.
My solution is to double teachers' salaries, regardless of how good they are, and wait one generation. Higher salaries will change public perception of the value of teachers, teaching will become a valued profession, admittance in teacher schools and in the job market will become highly competitive, and quality of teaching will improve. I know that's likely to be an unpopular option. People already think teachers are paid too much and do too little, which if you spend any time with teachers you know just ain't true.
Gates comes out at the end and has a few questions for him and is obviously taken with the concept. Perhaps some of the foundations resources will be backing Sal Khans approach? I am all for that. But like the article stated, it's his money.