I don't think Touch ID is that important on the iPad. If it's on the home button, which it looks like it is in the leaked images, it will be useless. Depending on how I have my case stand set up, the home button could be on the left or right. By the time I flip open the cover, and move my finger to the Touch ID, it seems that it would be a slower process than putting my password in. With the iPhone, my thumb is already in position to access the sensor.
I think it would be a win if there was a sensor embedded in the entire length of the bezel.