I don't think they are taking any exposers in the video, just getting a focus lock.
<doh!> well that's pretty pointless isn't it ?? What's the point of making AF 100ms faster when the inter-shot time is 2000ms?? Fingers crossed that the firmware not only improves AF speed marginally, but also allows the camera to walk and chew gum at the same time (it appears it can't write to SD while shooting, something my 20D could do 8 years ago).