This all goes to show that what we may consider to be relatively identical patents can be quite different, because the patents are for the underlying mechanism, not the general functionality that we talk about. For example, Google's new patent details the same mechanism as Apple's for recognizing various facial features, but seems to go well beyond that into a number of methods for logging in to a computer with the facial recognition. Additionally, where Apple's filing was specifically for iOS devices, Google's new patent covers any device with a camera, including smartphones, tablets, laptops, desktops, etc.
Of course, right now, all of this doesn't really matter all that much as Face Unlock is still something of a gimmick, and not a real security option. Jelly Bean's update to ask for blinking helps, but it can still be gamed fairly easily. Maybe by the time the technology is widely usable, the USPTO will have started working to fix the patent system.