Idemix, IBMs identity destroyer

Will it be usefull, or only useless piece of technology? IBM thinks, that too many places on internet colecting informations about you. So, they developed piece of software called Idemix (Identity Mixer). It should provide you privacy during online shopping by say checking your account ballance, but other side would only get message that its ok, not whole info about your money. Also it can check your age, without telling it to others. (hm, seems like hackers dream.. i can imagine that sbdy will hack it, and than buy everything from account without money) But to me seems it have a little mistake: What sense has to hide your identity from seller, if you must fill up your adress to take goods? But, may be it will have some sense.. Just wait until it will be completed.