The one with the power to vanquish the Dark Lord approaches...born to those who have thrice defied him, born as the seventh month dies...and the Dark Lord will mark him as his equal, but he will have power the Dark Lord knows not...and either must die at the hand of the other for neither can live while the other survives...the one with the power to vanquish the Dark Lord will be born as the seventh month dies...
To me that means Harry cannot truly live because he is Voldemort's seventh horcrux. Voldemort can't truly live without his soul being completely intact. The one with the power to vanquish the Dark Lord I think is Neville.
Either way, it sure is fun to speculate and debate.
And we know (because she told us so) that JKR was very careful of the wording of the prophecy. If we've learned nothing else from the books, the "obvious" answers to her mysteries are never the right ones.
The "obvious" view is that the prophecy applies to two people -- Harry and Voldemort. But why would JKR have to be so careful about the wording of that? It's so obvious that everybody would nod and say, "well, of course." The whole tension of the series would come down to Harry setting up his big fight with Voldemort ....yawwwwnnnnnn.....
No, she had to be careful about the wording of the prophecy because it does not mean the obvious thing. It means something unexpected.
You could be right when you say it'll be Neville, but I don't think so. I think Neville dies as Voldemort goes for the twofer: making sure that the prophecy really didn't apply to Neville, and also continuing the strategy of getting at Harry via his friends. Alternatively, Neville's increasingly impressive record of reckless bravery will prove to be his undoing, as he charges in to save Harry in a bad spot. Either way, poor Neville's a goner.
One of Fred and George probably die also -- at the wedding, probably. Ron was no doubt slated for death (playing the same role as Neville) but I think that with Neville dying, Ron gets a reprieve.