his statement is extremely broad, if two Xbox 360 owners bought a PS3 because of Killzone 2 his statement is instantly true. There is no way anyone can deny this fact because there is bound to be more that two Xbox 360 owns who bought a PS3 for Killzone 2 in the world.
So I have to give Sony credit, this statement is completely true, Killzone 2 has been successful at bringing X360 owners to the PS3. So congrats Sony on getting some X360 owners to buy a PS3.