My guesses (notice I don't use the word prediction):
Little big planet- 750,000-5,000,000 This game has so much potential and potential to completely bomb.
Resistance 2-3,500,000-5,500,000
Grand Turismo 5- 4,000,000-10,000,000 Racing games have died down a bit so I don't really know what to expect.
God of War 3- 2,500,000-4,500,000
Socom- 500,000-1,500,000
Killzone 2- 1,500,000-4,000,000 This all depends on whether it meets the hype or not