Someone elsewhere suggested that Voldemort wants Harry to kill the Death Eaters, who are obviously too stupid to live if they missed that trick.
I've seen it on a couple of other comment threads, but I think that Harry's understanding of time-causality is key here. If the lesson of the Comed-Tea is learned, it seems that efforts to defy prophecy are useless from the get-go.
But then I'm not practiced at arguing time-travel mechanics - can anyone else elaborate on this question?
This response is quite funny, now (in 2015) that we know what we know about why Harry is the way he is. EY was clearly chuckling to himself while reading this article.