I absolutely don't think that Draco will die on the bad side. I think that there is a possibility that he will be a "sacrificial lamb" after turning to the good side. I'm hoping that won't happen. I think it would be a better lesson to show that someone can make mistakes (even grave ones) and still be forgiven. Despite what Jo said in that interview, she did go to pains to make Draco sympathetic in book 6. Also, clearly, he loves his family and wants to protect them. And he has been brought up under their evil influence (esp that of his father). Which helps to explain (not excuse) his bigoted attitudes and arrogance. I think he has been brought down many pegs by Dumbledore's kindness to him, and it has to have changed him.
Guess we'll have to wait until next summer to find out!