I think Killzone is a solid game but it just misses that epic feeling of other scifi shooters like Halo and Mass Effect. The Hellgast are kinda interesting, but they just lack the personality to keep shooting them throughout the entire game. So it will need a new enemy that is scarier, better locations because the Nazi inspired buildings we seen in the killzone games just aren't that interesting. It needs bigger, wider levels, add vehicles and jetpacks and you got yourself a game that is guaranteed to sell a couple of millions.
Personally I hope they put Killzone to rest though. Horizon looks like a far more interesting franchise that they should build on. If that game has a dynamic day and night cycle and interesting enemies/ locations, it could very well become one of Sony's biggest franchises.
