Is continuous focus a 4.0-only feature? The http://www.android.com/about/ice-cream-sandwich/ page details that Android 4.0 "Ice Cream Sandwich" introduced two interesting features for Camera: &ldquo;continuous focus&rdquo; and &ldquo;zero shutter lag exposure&rdquo;.

Have both of these features been removed or disabled post 4.0?  My Galaxy Nexus seems to have neither since the 4.1 and 4.2 over-the-air upgrades.

Holding a 4.2 Galaxy Nexus still and taking a picture with auto settings and without flash in a relatively-very-well-lit nightclub takes about 3 seconds, and taking another picture right away takes another 3 seconds, seemingly indicating that both features are completely absent in stock 4.2.
In low light(or in very bright light) scenario, 'Zero shutter lag' feature won't work  because the camera module and the software together will do some heavy work to capture picture really good. Try taking picture in good lighting condition(during daytime) to test Zero shutter lag functionality. 

In some phones, Continuous focus makes use of accelerometer sensor to detect the movement of the phones to refocus the camera. This may not work when there is very slight movement. You can also check this during good lightning conditions