Story
Two years after the Helghast assault on Vekta, the ISA is bringing the fight to the enemy’s home world of Helghan. Taking the role of Sev, the battle-hardened veteran of the special forces unit known as the Legion, players will embark upon a mission to the planet Helghan to capture the Helghast leader, Emperor Visari, and bring the enemy’s war machine to a halt. For Sev and his squad, the invasion of Helghan is just the beginning. Tasked with securing Pyrrhus, the Capital City, the team quickly discovers that the Helghast are a formidable enemy on their home planet. Not only have they adjusted to the planet’s hostile conditions, they have also harnessed a source of power from the environment that can be used against the ISA. Sev and his team soon discover the fight is greater than simply addressing the enemy forces; the Legion must also learn how to handle the effects of the fierce enemy planet.
Gameplay
With Killzone 2, Guerrilla Games aims to provide the player with an immersive and cinematic gameplay experience that is grounded in reality with what they call "Hollywood Realism". The game is almost entirely presented from a first person point of view, through Sev's eyes. Killzone 2 features a cover system named "lean and peek" which allows the player to take cover behind an object, and then pop out to fire at enemies. The "lean and peek" mechanic stays in first person view at all times. Killzone 2 will also support PS3 Trophies. It has also been announced that Sev is able to pilot vehicles, however further details are yet to be announced. Many Killzone classic weapons and vehicles such as the the M82-G and the StA-52 LA will be returning.
Multiplayer
Killzone 2's multiplayer component has been developed by Guerilla Games in parallel with the game's single-player campaign. The multiplayer gameplay is class-based, meaning the player can choose a class of character which is specialized for a specific role to better suit the player's needs in battle. There will be 16 abilities(badges) in total in which the player can mix and match 2 of them according to their playing style, and can switch abilities upon death. 32 players can connect online, and group into squads of up to four players. Two squads can group together as a faction of eight players. Killzone 2 also offers a clan system, which allows clans of up to 64 players to compete for "Valor Points", an in-game currency that clans can use to bet on tournaments.
Link
Above is the newest trailer for Killzone 2. You can watch it in hi-definition here
Killzone 2 is set for a February 2009 release and is exclusive to the playstation 3 platform