Children, please. No need to get all bent out of shape about a game.
Regardless, I think that GT5's sales will be almost 3-4x out of the US, and will sell big time. I hardly care much for the game at this point, but I know this will be great racing game for those who like racing games, especially given the plethora of value tucked into the game.
Despite this, I do not think the numbers will be as large as people claim. Hands down will be PS3's best exclusive by a substantial margin.