As richardhutnik said Sony want a flagship shooter for the PS3, Killzone 2 will be the game. MS have two monsters in Halo and Gears, Sony do not have a single one however this is where the differences between the demographic of 360 and PS3 owners come into play.
Sony's flaghip game is GT, Sony do not need Killzone 2 to be as big as Halo because they have a bigger franchise already. Killzone 2 will sell nicely, I say 3 million if Sony do their trademark shitty advertising. Another one is MAG, I am willing to be my dentistry degree that the name of that game will be SOCOM: ???? to get huge sales for that game, shove that name into the title and Sony have themselves a big seller.
This is where I truly feel sorry for Naughty Dog, Guerrilla, Insomniac etc, MS and Nintendo would make those into huge sellers but Sony? Nope
