Given the barren spell we're enduring with retail releases just now, we'll take everything we can get! New Killzone 2 maps "Suljeva Cliffside" and "Arctower Landing" should do very nicely. Both are set in locations taken from the single-player; Suljeva taking place near the mining village and Arctower in the urban hotzone of Blood Meridian.
Guerrilla will also allow players to use the flamethrower and bolt gun respectively on the new maps. They won't be available on any of the older maps.