Why everyone thinks Killzone 2 will be huge?

[Slimebeast]

Killzon 2 will sell well but not very special. Rufly 2.5 mill ww lifetime. 3 mill at best (if bundled and stuff).

Rufly 90% on Gamerankings.

Can someone link to a clip that shows those amazing grafix BTW? Gameplay that shows how supposedly superb grafix it has. So far I have seen none really.