I don't know the nuts and bolts.
I just know that the Supreme Court said that the individual mandate was constitutional, which is apparently a very good thing. And then I had to turn CNN off, because it was driving me up the wall, and I haven't been back.
But I can see from Twitter that the "Obamacare" people seem good and riled up, so I take it that something significant did indeed happen to advance affordable health care for all Americans.
Good. It's about time. :)
Here are some reading resources about the decision: http://www.shakesville.com/2012/06/scotus-decision-on-affordable.html