I'm curious - going from a D200, and your profile says you mainly do portraits -- why a D3 or D4, why not a D800. For portrait work you will get better images (IMO) at half the cost. I'd go D4 (or D3s) more for sports, very high ISO (though the D800 is awfully good there). But for portraits?
PS. I love the D4, and have both it and a D800, so I'm not knocking either one. Just noticing your profile and thought it worth a mention.