Some of the requirements that are supposed to lower rates (setting %'s that must be spent on patient care and the insurance markets) will actually raise rates.
Some of the stuff that was obviously going to raise rates (including more high risk patients) may or may not raise rates based on how much an individual insurance company is able to also attract additional low risk patients (since now more people will have to get coverage that didn't before).
The way a lot of insurance companies are set up today they will have a hard time adjusting to the changes in any way other then strictly raising prices and the trend of late has been that those hikes are passed directly to the consumer (businesses no longer just eat up a price hike). Given a bit of time though companies will find new ways to do business within the guidelines to lower costs. A big piece of this is going to get health care providers into the 21st century technologically so they can better manage information and care and reduce their own cost of doing business with payors.