Source C&VG

A few details have emerged on Killzone: Liberation, a spin-off from the first-person shooter series that's infiltrating PSP. Liberation, which is being developed by Guerilla Games, ditches the first-person viewpoint for a third-person angle, implying that tactical gameplay has been given greater consideration in this title. According to a report in Official PlayStation Magazine, the storyline follows on from the plot of Killzone on PS2, players reprising the role of killer trooper Jan Templar. Armed with an array of new firepower and attacks, he'll be battling the militaristic separatist faction Helghast.

Screenshots from Liberation are doing the internet rounds, but if we posted them here large men in balaclavas and wielding big guns would break down the office door and wheel us away to never be seen again. Still, from what we've seen, graphically it's pretty decent with the pics showing industrial/headquarters environments; and with plenty of cover apparent, it's clear that stealth is going to play a role too. In fact, looking at the shots it reminds us a little of the first Metal Gear Solid game.
Sony was unavailable from comment on Killzone: Liberation at the time of writing so no further info from that quarter just yet, but hopefully we'll have more details - including official screenshots - soon.