The new version of the AF Assist tool will use a similar laser pointer but have the function of it be controlled by the camera and not the push button.
I know there is a pin on the hotshoe that gets energized by the 1/2 push of the camera shutter button. This is the AE-Lock feature of the camera. I know this because my wireless trigger has an LED on it which goes green at the half press of the shutter button. The LED goes red with a full shutter button press.
What I want to do is trigger the AF assist light to come on when the AE-Lock (1/2 press of shutter) button is pushed, and turn off the AF Assist light when not pushed.
The other thing I need is for the AF light to momentary go off when the flash is triggered so not to record the AF light into the image.
UPDATE : See this post for the first builds