I don't think having an IPhone instead of a camcorder would fit the general atmosphere of the games... though a camcorder is rather big and noticeable for enemies, not to mention you've always gotta recharge it at some point.
It would be good if the next game came up with a new idea to record the events, like a more discreet small gadget that doesn't need new battery several times, only at save points or something like that