I wouldn't call it a prisoner's dilemma - competitors that oppose HFCS have no incentive to make the switch as the perception (or reality) of better taste/healt

I wouldn't call it a prisoner's dilemma - competitors that oppose HFCS have no incentive to make the switch as the perception (or reality) of better taste/health are their top selling point. You don't fill up on salad before a pie eating contest and you don't get into the ring with Coca-Cola on their terms. The problem here is that Coke has to decide between a unified front and hedging their bets. One way kind of undermines the other.