Read this interesting article today from marketwatch about the nuances in how stocks may react to today's historic health care decision.

http://www.marketwatch.com/story/look-for-nuances-in-health-stocks-after-ruling-2012-06-27?dist=beforebell

The handicappers say the strongest chance is of the individual mandate being overturned and everything else staying the same:

"What is more likely, he says, is that justices will strike down the individual mandate requiring everyone to buy insurance, which he calculates as having a 60% to 70% chance of occurring. If only that part of the bill is struck down, it will put pressure on insurers, who still will be forced to offer coverage to everyone."

A lot of different outcomes may still happen.  But I'm going to bet it won't be good for health insurers.  If nothing else, changes to the law will create a cloud of uncertainty that discourages buyers.