I was browsing around Evil Avatar and I came across a post linking to an interview with Mathijs de Jonge, the Game Director and Lead Designer of Killzone: Liberation.
The player can not directly control the camera. However we’ve designed the camera so that there is never a need or a desire for it. What happens is that as soon as an enemy approaches the player the camera will intelligently pan and zoom to frame the situation in the best possible way. This happens so subtlety that the player in most cases won’t even notice. We designed a camera system we call PICS, Pseudo-isometric Intelligent Camera System.
Go give it a read. Via Evil Avata.