Re: Killzone 3 Splitscreen :

Yes killzone 3 is splitscreen co – op!!!!

http://au.gamespot.com/ps3/action/killzone3/news.html?sid=6285485&om_act=convert&om_clk=picks&tag=picks;title;9&mode=previews

“Circling back to the start of the demo, you're given the option to play either solo or via split-screen co-op. This is, of course, a brand-new feature for Killzone 3.”