I think it will be 12 millions PS3 sold in June (if MGS4 is released in June ^^ )
I don't know if it's the case in North America , but the game is very expecteed in Europe ! So my numbers are :
Europe : 400 k
Japon : 150 k
NA : 150k-300k
Total : 700k-850k
And Sony said it would be a pack in Europe , so I think the game will be sold 4 millions at the end of it life