Which best seller will have the most sales week 1 world wide?

[CommonMan]

1st week: Halo reach, I think 4 million isn't out of the question, 3 million almost for sure.
Lifetime: Very close between GT5 and Halo:Reach, I could see them both doing 11 million.
SMG2 will probably do half those numbers.

Edit: Hey! 2,000 posts, I feel good about this one too, hooray!