Just read on CNN that nationwide SAT scores this year had their biggest drop in 31 years. Various reasons are given, including the fact that the test format changed this year and the price to take the test went up.
Anecdotally it seems like SAT scores have been on this downward trend for decades so I did some searching and found an interesting paper about the SAT test. It made me realize that designing an ideal test is a hard if not impossible task, and that as much as the College Board says otherwise all those SAT coaching programs really can make an impact. Which goes back to the argument whether the test reflects aptitude or demographics - because there definitely is a correlation because family income and the likelihood a student will enroll in a coaching program. I also liked the part where the author mentions that the students of 1926 (the first year the SAT was administered) faired poorly because they felt guessing on a multiple choice test was immoral!