Interesting comments on the "wolf" reaction David, as it explains the erratic action of deer when in close proximity to a potential crash. I have swerved to avoid a deer hit, when in a car, only to have the deer suddenly turn right back into my path and a crash resulted with a lot of vehicluar damage.
Given that, I too feel the only "somewhat" reliable REACTION is to get HARD on the brakes in a straight line. If directional control is possible, aim for the deer's butt, so its not there when you get there, hopefully.
But really, the only PROACTION choice is to always expect deer when the terrain and conditions "seem" right for them, and slow down. Yesterday, driving my company car, I had a large doe sprint at near full speed right across HWY 2 in Upper Michigan, right in front of me, at about 6:30pm, in bright sunlight, not more than a mile south of Crystal Falls (an area known for many deer).