I would not be surprised if the pool of applicants signing up for Obamacare are sicker in general then the 2014 pool because those who intended to take the penalty and not sign up in 2015 would most likely apply if they did get chronically sick in the intervening period which would escalate premium rates for the pool even further.
Bingo! Drip by drip, the only people who consider health insurance worth the price of the exorbitant premiums are the chronically sick. As premiums skyrocket, healthy people drop out of the pool. Death spiral 101. All part of the plan which will lead us to single payer.