What Could Have Been: Jason would have survived if the result of the phone poll had gone the other way. There's even an alternate ending to the issue where Jason dies, with Batman holding his body before proclaiming Jason was alive. In any case, Jason's mom was doomed to die. Not that she didn't deserve it, mind you.
Had Jason survived, he would've ended up in a coma, with no one having any idea as to when, or if, he'd ever wake up. Beyond this, it seems nobody had any other plans for the character.