Halo Killer?

With the release of Killzone 2 fast approaching there is talk about this game being a "Halo killer" or can it be a "Halo killer" and I am sick of people saying that this game will never be a "Halo killer" because they are on different systems. It seems that every year or every few years there is a game released on the Playstation that people call the "Halo killer" but yet Halo still sells well and that is because the two games are on different systems and they are exclusive to that system which makes it virtually impossible for that game to kill Halo. The only way Halo will be killed is if there is an awesome game released either exclusively on the Xbox or is on both the Xbox and the Playstation. So please stop saying that games that are exclusive to the Playstation will be a "Halo killer" because it simply will not be, however the game could sell very well on the Playstation but Halo will still continue to very well on the Xbox.