Most interesting aspect of this patch? Further refinement of the game's occasionally maligned analog controls, which are getting a whole new "high precision" mode via this update that you can turn on or off. Quoth a Guerilla rep:
When this option is switched on, it makes the analog sticks more responsive to small movements. Turned off, the controls behave exactly as they did before the patch. It’s not a radical overhaul of the control system, so the layout and the ‘weight’ of the controls remain the same.
Still, a lot of us here at Guerrilla really enjoy the new High Precision option, so we’ve decided to switch it on by default for new players. Existing Killzone 2 players will have the option turned off by default after patching – we wouldn’t want to force a sudden change to the controls on you!
As someone who burned out on Killzone 2's campaign halfway through and would cite the controls as at least one reason why, I hope this will be enough to get me through the back half of the game's single-player portion. But then, I hope this new mode is even applicable to the campaign, come to think of it, since the rest of the update seems focused on matchmaking, game balance, and other issues that primarily affect multiplayer.
Head over to the official Blog de PlayStation for the full rundown of what's new in patch 1.27.