This is the key takeaway for me from the article (and also supports my own beliefs). If teachers in the US started earning like doctors and lawyers ($100K-$200K), then many of our education problems would go away. Why? You'd start retaining good teachers, and attracting new, good teachers. Then these folks would continue to solve education problems. You'd be amazed at what highly paid, motivated professionals can accomplish. But low-paid teachers, no matter how dedicated, get burnt out a few years into a career. Bad teachers would eventually work their way out, due to increased competition. (Read the article about how applications shot up.) Some of the money (thought not all) for higher salaries is in education, but it's just not being spent in the right places.
The 2nd interesting point I took away is the ability grouping. Not grouping by ability works for young children, say K-6. But once older, the gap is too much for a unified curriculum. Taking this concept further out, Americans need more vocational high schools, like Finland. College is overvalued in this country, and a large segment of high school students are being misled by the college myth.