It may not become the norm very soon, but is operational for both inbound and outbound at Helsinki. It's not completely reliable, several gates rejected my passport inbound and I had to go to the manned desk.
On the way out, the machine read my passport and recognised my face, even though I was wearing glasses on the day but not in my passport photo.
I assume that the chip holds a copy of the photograph, and clever software matches it with what the camera sees. There are a number of published International Standards to do with aspects of biometrics, for example ISO/IEC 19794-5:2005 Information technology -- Biometric data interchange formats -- Part 5: Face image data
Anyone can buy a copy from ISO or their local National Standards Body (BSI, DIN, AFNOR, ANSI, etc) for 150 Swiss Francs or the local equivalent.