I'm going to be bold, why? because only Uncharted 2 has been out just over a year, the other 2 have done great sales in less than a year, in GT5s case just about a month.
Uncharted 2: 5-6 mil
God of War 3: 5 mil
Gran Turismo 5: no idea maybe 9 mil, but its had so much bad press, i'm not sure if 10 mil is possible for this GT. but GT4 did 10 mil in about 4 years, GT5 could end up doing 11 mil in 4 years, its hard to predict these things.