Well - actually, there's an enormous amount of religious symbolism in Rowling's series, as there is not in LeGuin's - it's not just the phoenix. And part of that symbolism is the constant reference to the power of willing sacrifice. That's why I think Harry will probably die defeating Voldemort. But if he does live, it's quite possible he will lose his powers. (And I would not call that a defeat or a sad ending, because the wizarding world, IMHO is a cruel and chaotic place.) But, of course, those are just my theories! We'll have to wait and see what Rowling actually does. )