Considering that pre-orders in EU only are about 1.1 millions; I would say that at its very least the game will sell in the first week 1.5m worldwide.
But considering that A LOT people buy games without a pre-order, and that when the game releases it will only have 3 days to sell for before the week ends; I think it could sell worldwide 2-3Millions the first week.
What I am saying is, if the 1.1m pre-orders are from costumers and not from stores (obviously).








