Alright Summer 2010 it is then:
Well given that it definitely gives Sony enough time to ramp up hyping and advertising which so far has been nonexistent for such a big title. Assuming they give this AAA treatment (which they will) I think a 2.4-2.8 million opener isn't out of the question for the extremely loyal PS3 fanbase they have right now. If I had to do the splits:
Americas- 800k
E/O- 1.2 million
Japan- 600k
By the end of the year it should easily be in the 5-6 million range given that it came out in summer. Not to mention I would expect some bundling of the title in Europe and potentially Japan at release. Depending on the longevity of that bundling could affect sales but I would say the game should, given PS3 userbase and popularity of the brand, to hit the 9-11 million range. As for systems pushed on the day it launches, given they all launch in the same week, could push it up in the 300k-400k range (remember this is summer haha).
Now these are all some very big ifs haha. Things that could affect this prediction are of course potentially a fallout of simulation racers this generation which there really haven't been any huge ones yet, of course GT is the biggest branded one of them all. Second, could be potentially PS3 fallout in 2010 which is possible, although maybe not as likely as it used to be. Finally, the biggest problem could be competition from other big name games in the year. No telling what will release by it and so far first party Sony games haven't stood up well to the big 3rd party offereings.
However, despite all of that, I think like my predictions given the release date stands and a few other assumptions.