PSBlog- "To celebrate Killzone 3’s first anniversary, we’re releasing a standalone version of the game’s online component on PlayStation Store today. Dubbed “Killzone 3 Multiplayer,” it includes the Guerrilla Warfare, Warzone, and Operations game modes, as well as the original Killzone 3 maps and all Killzone 3 DLC maps. Best of all, it’s free to try – you can play any of the maps and modes until you reach the rank of Sergeant I.
For those who already own Killzone 3 (or decide to purchase the full version of Killzone 3 Multiplayer), we have another anniversary treat: this weekend will be Double XP Weekend! Starting on Friday, March 2 at 8:00am Pacific time, and lasting until Monday, March 5 at 2:00am Pacific time, all XP earned in online Killzone 3 matches will be doubled."