It's a very interesting concept; My mum uses something similar for accessing her workplace computer at home.
Maybe.. but it will take some time before hackers get to it. Perhaps by the time they get around to cracking it, there will be a newer type of credit card system. The corporation my mum works for have used similiar tech for over 5 years now and they haven't been hacked .. yet.
maybe there isn't a need to hack her corporation and with something to gain hackers have something to gain from it so therefore will find a way... unless the key given after the pin is entered can be randomized the pin will be stored somewhere in the chips memory... but for the randomization to happen the card must authorize the generated number with the credit card database... but who is to say that can't be spoofed?