The health care law will hinge on two judges: Roberts and Kennedy ...

So pretty much Obama's Solicitor General may have single-handedly lost the Supreme Court battle on health care.  Now all eyes are on justices Roberts and especially Kennedy, who will be the deciding votes on the individual mandate:

At this point, it seems likely that Obamacare’s fate will hinge on whether Justice Roberts or Justice Kennedy come to believe there is a “limiting principle” under the government’s theory of the individual mandate. If either one, or both, can see that there is a clear limit to federal power in a universe where the mandate is constitutional, the law may be upheld. If not, the mandate could go down.

The way I see it, if there is going to be a health care exchange, insurance companies aren't going to participate if patients wait until they are sick before using it.  That would be a losing proposition that would drive up health care costs.  So the only way to give Americans greater access to coverage and have insurance companies willing to participate is if people are required to buy health insurance from the start.  Everyone would be covered, and preventive care would drive down the cost for everyone else in the long run.