The classic measured target formula for a head and shoulders pattern is to subtract the peak from the neckline, add that value to the neckline, and voila, you have your target. In the case of the Russell (as viewed here through the IWM), the target was $44, and that has been reached (I've drawn tinted areas for easy viewing).
As I've pointed out before, the most incredible thing is that only five weeks ago the IWM was at its highest value ever in human history.