i see what you're saying, but the prophecy says more than just that. it also tells us that harry is the only one who can kill voldemort which would make it a perfect reason for introducing the prophecy. there's more hidden in the prophecy, lots of it will come up again, i'm sure.
but i agree with you about voldemort dying, mostly. i think he's gonna be defeated and most of the time i believe harry will survive. (other times i'm not too sure). i just can't help but think that it's too easy and there has to be something unexpected about the ending of the book....after all, it is jk.