Face detection is on 2.3.6 roms as well as most ICS/JB roms (ICS though needs a seperate addon which can be downloaded from the Gapps page)
Smile detection, not a clue why- however the Face Unlock methods used above use blink detection (2.3.6 uses it by default, ICS/JB make it an option)
Sent from my GT-P7510