While Activision is not talking numbers yet, Analysts that we spoke with tell us that retailers could have as many 9 million copies of Call of Duty Modern Warfare 3 pre-ordered. If that isn’t enough, several analysts suggest that the first day of sales could top 6 million worldwide, with 9 million sold by the end of the week. If this comes to pass, it will be the fastest selling game ever released.

An analyst we spoke with says that by the time the dust settles he fully expects Activision to sell between 27 and 30 million copies of the game, which is more than the two previous releases in the franchise. Activision is said to be prepared for the sales, and retailers should have plenty of copies to fill all of their pre-orders and enough extra for those who didn’t pre-order.

It isn’t clear how much impact Battlefield 3 will have on Modern Warfare 3 sales. Several retailers we spoke with expected to see a lot of copies traded in for Modern Warfare 3. “Let them trade in Battlefield for Modern Warfare 3, as we still have plenty of customers looking for used copies of Battlefield 3 despite the use of its online pass,” one retailer told us.