It really doesn't work that well any way. I used it for a while on my Nexus, but I got tired of having it fail and having to enter my pattern to unlock. I found it faster just to have pattern lock enabled since I was using that 90% of the time any way.
I've been playing with ICS for almost 24hrs now and where's the facial recognition unlock/lock screen integration?????
You're not missing much. Used it for a month or so on my Galaxy Nexus and finally switched back to the pattern as it wasn't very secure and didn't work well in low light. My son was able to unlock my phone using his face one time.