I think it will depend a lot on whether Sony drop the PS3 price to $299 or not.
Ratchet has a more casual appeal compared to other Sony exclusives. I should think a lot of people who bought Ratchet on the PS2 haven't got a PS3 because they are the sort of people who don't spend $399 on a PS3. Therefore I predict:
Without price-cut: 1.8M
With price-cut: 2.1M








