I stopped reading some of the replies cuz I am lazy.... :P
But I just wanted to say that the bonus you get from X racial really is not worth rerolling a 76. If you have a lot of time on your hands or you are really set on getting a racial that will benefit you, do it to it. Human would probably be the best choice for raiding, with the Spirit boost. The others would have PVP benefits (Nelf: Shadowmeld and 2% hit reduction, Draenei: Insta-heal and +hit, Dwarves: stoneform, even though it is nerfed from previous awesomeness). Really though, none of those are so amazing that you would need to reroll for them. (and being able to shadowmeld and save yourself a death is supersweet :P)