The sensor is epi-dermal, which means reads underneath the skin, so it does not solely rely on seeing the prints. There is a steel ring, which probably senses capacitance. Will there be exploits? Probably. Are Apple engineers incompetent to think of obvious exploits? I would put my money on NO.
In any case, I would like to see the evolution of this tech.
> Are Apple engineers incompetent to think of obvious exploits? I would put my money on NO.
They may have thought of them, but they didn't solve them for the very simple reason that it's impossible to solve them.
A fingerprint is only secure for causal use (someone picking up your phone), but it's worthless for any more security than that. It's like the face recognition on an android phone - good for causal use, but easily defeated.
A few years ago, some students from my local university went around to all of the fingerprint solution companies that were exhibiting at the CeBIT fair. All of the products that the respective companies agreed to be challenged were in fact fooled by something that originated as a fingerprint on a drinking glass.
Iphone will be out soon, pretty sure hacking/fooling fingerprint sensor is top priority for lot of people. So we will see if this common methods works on not.
AFAIK capacitance of your skin can change very frequently and rapidly. Drink too little for two days -> skin dry -> resistance goes up steeply. Even using a touchpad for an hour might dry your skin up (sidenote: I sometimes even have to moisten my fingers so my MBP touchpad registers my touches well).