The Obamacare ruling is taking a long time to be delivered. Many people were expecting it today. I haven't heard this anywhere, but I was just thinking that perhaps the delay in issuing the ruling is partly due to the fact that they are striking down large parts of the law and therefore it is a long and complicated opinion to write. If you recall, during oral arguments Scalia was joking about how much work it would be for his clerks to go through the law and determine which parts to keep and which to throw out.
I'm no Supreme Court expert, but a delayed ruling would seem to increase the chances that it is partially overturned. I also noticed that the Intrade odds in favor of overturning have been going up as we wait longer and longer for the ruling.