Class Mobility in America?

The New York Times offered on Sunday an intriguing introduction to a series on Class in America they are running this week.
Called "Class in America: Shadowy Lines That Still Divide", it is a fascinating read. Where social science crosses with economics, I have great interest.
The article's basic premise seems to be that class mobility is decreasing in America due to a variety of factors.
I can't say I disagree with anything in the article, although I am a firm believer that with hard work, anyone can achieve success. That hard work must be applied towards getting a great education, however. There inlies the problem, though, as in order to get a great education, one must really begin scoring quite well in school as a 7th grader, which likely won't happen if you didn't before then, and likely won't happen if there's nobody in your life telling you that school/education matter.
I'd be curious what others think.